Merge tag 'tty-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial driver updates from Greg KH:
"Here is the big set of tty and serial driver updates for 5.16-rc1.

Nothing major in here at all, just lots of tiny serial and tty driver
updates for various reported things, and some good cleanups. These
include:

- more good tty api cleanups from Jiri

- stm32 serial driver updates

- softlockup fix for non-preempt systems under high serial load

- rpmsg serial driver update

- 8250 drivers updates and fixes

- n_gsm line discipline fixes and updates as people are finally
starting to use it.

All of these have been in linux-next for a while now with no reported
issues"

* tag 'tty-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (86 commits)
tty: Fix extra "not" in TTY_DRIVER_REAL_RAW description
serial: cpm_uart: Protect udbg definitions by CONFIG_SERIAL_CPM_CONSOLE
tty: rpmsg: Define tty name via constant string literal
tty: rpmsg: Add pr_fmt() to prefix messages
tty: rpmsg: Use dev_err_probe() in ->probe()
tty: rpmsg: Unify variable used to keep an error code
tty: rpmsg: Assign returned id to a local variable
serial: stm32: push DMA RX data before suspending
serial: stm32: terminate / restart DMA transfer at suspend / resume
serial: stm32: rework RX dma initialization and release
serial: 8250_pci: Remove empty stub pci_quatech_exit()
serial: 8250_pci: Replace custom pci_match_id() implementation
serial: xilinx_uartps: Fix race condition causing stuck TX
serial: sunzilog: Mark sunzilog_putchar() __maybe_unused
Revert "tty: hvc: pass DMA capable memory to put_chars()"
Revert "virtio-console: remove unnecessary kmemdup()"
serial: 8250_pci: Replace dev_*() by pci_*() macros
serial: 8250_pci: Get rid of redundant 'else' keyword
serial: 8250_pci: Refactor the loop in pci_ite887x_init()
tty: add rpmsg driver
...

Documentation/devicetree/bindings/serial/8250_omap.yaml

···
   - reg
   - interrupts
 
-additionalProperties: false
+unevaluatedProperties: false
 
 if:
   properties:

Documentation/devicetree/bindings/serial/brcm,bcm6345-uart.txt

···
-* BCM63xx UART
-
-Required properties:
-
-- compatible: "brcm,bcm6345-uart"
-
-- reg: The base address of the UART register bank.
-
-- interrupts: A single interrupt specifier.
-
-- clocks: Clock driving the hardware; used to figure out the baud rate
-  divisor.
-
-
-Optional properties:
-
-- clock-names: Should be "refclk".
-
-Example:
-
-	uart0: serial@14e00520 {
-		compatible = "brcm,bcm6345-uart";
-		reg = <0x14e00520 0x18>;
-		interrupt-parent = <&periph_intc>;
-		interrupts = <2>;
-		clocks = <&periph_clk>;
-		clock-names = "refclk";
-	};
-
-	clocks {
-		periph_clk: periph_clk@0 {
-			compatible = "fixed-clock";
-			#clock-cells = <0>;
-			clock-frequency = <54000000>;
-		};
-	};

Documentation/devicetree/bindings/serial/brcm,bcm6345-uart.yaml

···
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/brcm,bcm6345-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: BCM63xx UART
+
+maintainers:
+  - Rafał Miłecki <[e-mail]>
+
+allOf:
+  - $ref: serial.yaml#
+
+properties:
+  compatible:
+    const: brcm,bcm6345-uart
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: refclk
+
+unevaluatedProperties: false
+
+required:
+  - reg
+  - interrupts
+  - clocks
+
+examples:
+  - |
+    serial@14e00520 {
+        compatible = "brcm,bcm6345-uart";
+        reg = <0x14e00520 0x18>;
+        interrupt-parent = <&periph_intc>;
+        interrupts = <2>;
+        clocks = <&periph_clk>;
+        clock-names = "refclk";
+    };

Documentation/devicetree/bindings/serial/samsung_uart.yaml

···
           - samsung,s3c6400-uart
           - samsung,s5pv210-uart
           - samsung,exynos4210-uart
+          - samsung,exynos850-uart
 
   reg:
     maxItems: 1

Documentation/devicetree/bindings/serial/sprd-uart.yaml

···
           - enum:
               - sprd,sc9860-uart
               - sprd,sc9863a-uart
+              - sprd,ums512-uart
           - const: sprd,sc9836-uart
       - const: sprd,sc9836-uart
 

Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.txt

···
-Xilinx Axi Uartlite controller Device Tree Bindings
----------------------------------------------------------
-
-Required properties:
-- compatible		: Can be either of
-				"xlnx,xps-uartlite-1.00.a"
-				"xlnx,opb-uartlite-1.00.b"
-- reg			: Physical base address and size of the Axi Uartlite
-			  registers map.
-- interrupts		: Should contain the UART controller interrupt.
-
-Optional properties:
-- port-number		: Set Uart port number
-- clock-names		: Should be "s_axi_aclk"
-- clocks		: Input clock specifier. Refer to common clock bindings.
-
-Example:
-serial@800c0000 {
-	compatible = "xlnx,xps-uartlite-1.00.a";
-	reg = <0x0 0x800c0000 0x10000>;
-	interrupts = <0x0 0x6e 0x1>;
-	port-number = <0>;
-};

Documentation/devicetree/bindings/serial/xlnx,opb-uartlite.yaml

···
+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/serial/xlnx,opb-uartlite.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xilinx Axi Uartlite
+
+maintainers:
+  - Peter Korsgaard <[e-mail]>
+
+properties:
+  compatible:
+    contains:
+      enum:
+        - xlnx,xps-uartlite-1.00.a
+        - xlnx,opb-uartlite-1.00.b
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  port-number:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Set Uart port number
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: s_axi_aclk
+
+  current-speed:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The fixed baud rate that the device was configured for.
+
+  xlnx,data-bits:
+    enum: [5, 6, 7, 8]
+    description:
+      The fixed number of data bits that the device was configured for.
+
+  xlnx,use-parity:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1]
+    description:
+      Whether parity checking was enabled when the device was configured.
+
+  xlnx,odd-parity:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [0, 1]
+    description:
+      Whether odd parity was configured.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - current-speed
+  - xlnx,data-bits
+  - xlnx,use-parity
+
+allOf:
+  - $ref: /schemas/serial.yaml#
+  - if:
+      properties:
+        xlnx,use-parity:
+          contains:
+            const: 1
+    then:
+      required:
+        - xlnx,odd-parity
+
+unevaluatedProperties: false
+
+examples:
+  - |
+      serial@800c0000 {
+        compatible = "xlnx,xps-uartlite-1.00.a";
+        reg = <0x800c0000 0x10000>;
+        interrupts = <0x0 0x6e 0x1>;
+        port-number = <0>;
+        current-speed = <115200>;
+        xlnx,data-bits = <8>;
+        xlnx,use-parity = <0>;
+      };
+...

Documentation/driver-api/serial/n_gsm.rst

···
 
 How to use it
 -------------
-1. initialize the modem in 0710 mux mode (usually AT+CMUX= command) through
-   its serial port. Depending on the modem used, you can pass more or less
-   parameters to this command,
-2. switch the serial line to using the n_gsm line discipline by using
-   TIOCSETD ioctl,
-3. configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl,
-4. obtain base gsmtty number for the used serial port,
+1. config initiator
+^^^^^^^^^^^^^^^^^^^^^
+
+1.1 initialize the modem in 0710 mux mode (usually AT+CMUX= command) through
+    its serial port. Depending on the modem used, you can pass more or less
+    parameters to this command.
+1.2 switch the serial line to using the n_gsm line discipline by using
+    TIOCSETD ioctl.
+1.3 configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl.
+1.4 obtain base gsmtty number for the used serial port.
 
 Major parts of the initialization program :
 (a good starting point is util-linux-ng/sys-utils/ldattach.c)::
···
 	daemon(0,0);
 	pause();
 
-5. use these devices as plain serial ports.
+1.5 use these devices as plain serial ports.
 
    for example, it's possible:
 
    - and to use gnokii to send / receive SMS on ttygsm1
    - to use ppp to establish a datalink on ttygsm2
 
-6. first close all virtual ports before closing the physical port.
+1.6 first close all virtual ports before closing the physical port.
 
    Note that after closing the physical port the modem is still in multiplexing
    mode. This may prevent a successful re-opening of the port later. To avoid
···
    for the second time. The byte sequence for the disconnect command frame is::
 
       0xf9, 0x03, 0xef, 0x03, 0xc3, 0x16, 0xf9.
+
+2. config requester
+^^^^^^^^^^^^^^^^^^^^^
+
+2.1 receive string "AT+CMUX= command" through its serial port,initialize
+    mux mode config
+2.2 switch the serial line to using the n_gsm line discipline by using
+    TIOCSETD ioctl.
+2.3 configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl.
+2.4 obtain base gsmtty number for the used serial port,
+
+  #include <stdio.h>
+  #include <stdint.h>
+  #include <linux/gsmmux.h>
+  #include <linux/tty.h>
+  #define DEFAULT_SPEED	B115200
+  #define SERIAL_PORT	/dev/ttyS0
+
+	int ldisc = N_GSM0710;
+	struct gsm_config c;
+	struct termios configuration;
+	uint32_t first;
+
+	/* open the serial port */
+	fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY);
+
+	/* configure the serial port : speed, flow control ... */
+
+	/* get serial data and check "AT+CMUX=command" parameter ... */
+
+	/* use n_gsm line discipline */
+	ioctl(fd, TIOCSETD, &ldisc);
+
+	/* get n_gsm configuration */
+	ioctl(fd, GSMIOC_GETCONF, &c);
+	/* we are requester and need encoding 0 (basic) */
+	c.initiator = 0;
+	c.encapsulation = 0;
+	/* our modem defaults to a maximum size of 127 bytes */
+	c.mru = 127;
+	c.mtu = 127;
+	/* set the new configuration */
+	ioctl(fd, GSMIOC_SETCONF, &c);
+	/* get first gsmtty device node */
+	ioctl(fd, GSMIOC_GETFIRST, &first);
+	printf("first muxed line: /dev/gsmtty%i\n", first);
+
+	/* and wait for ever to keep the line discipline enabled */
+	daemon(0,0);
+	pause();
 
 Additional Documentation
 ------------------------

Documentation/driver-api/serial/tty.rst

···
 hangup()		Called when the tty line is hung up.
 			The line discipline should cease I/O to the tty.
 			No further calls into the ldisc code will occur.
-			The return value is ignored. Can sleep.
+			Can sleep.
 
 read()			(optional) A process requests reading data from
 			the line. Multiple read calls may occur in parallel

arch/sh/boot/dts/j2_mimas_v2.dts

···
 			clock-frequency = <125000000>;
 			compatible = "xlnx,xps-uartlite-1.00.a";
 			current-speed = <19200>;
+			xlnx,use-parity = <0>;
+			xlnx,data-bits = <8>;
 			device_type = "serial";
 			interrupts = <0x12>;
 			port-number = <0>;

drivers/bluetooth/hci_ldisc.c

···
 		break;
 
 	default:
-		err = n_tty_ioctl_helper(tty, file, cmd, arg);
+		err = n_tty_ioctl_helper(tty, cmd, arg);
 		break;
 	}
 

drivers/input/serio/serport.c

···
 }
 #endif
 
-static int serport_ldisc_hangup(struct tty_struct *tty)
+static void serport_ldisc_hangup(struct tty_struct *tty)
 {
 	struct serport *serport = (struct serport *) tty->disc_data;
 	unsigned long flags;
···
 	spin_unlock_irqrestore(&serport->lock, flags);
 
 	wake_up_interruptible(&serport->wait);
-	return 0;
 }
 
 static void serport_ldisc_write_wakeup(struct tty_struct * tty)

drivers/net/can/slcan.c

···
 	/* This will complete via sl_free_netdev */
 }
 
-static int slcan_hangup(struct tty_struct *tty)
+static void slcan_hangup(struct tty_struct *tty)
 {
 	slcan_close(tty);
-	return 0;
 }
 
 /* Perform I/O control on an active SLCAN channel. */
···
 		return -EINVAL;
 
 	default:
-		return tty_mode_ioctl(tty, file, cmd, arg);
+		return tty_mode_ioctl(tty, cmd, arg);
 	}
 }
 

drivers/net/hamradio/6pack.c

···
 			break;
 		}
 	default:
-		err = tty_mode_ioctl(tty, file, cmd, arg);
+		err = tty_mode_ioctl(tty, cmd, arg);
 	}
 
 	sp_put(sp);

drivers/net/ppp/ppp_async.c

···
  * Wait for I/O to driver to complete and unregister PPP channel.
  * This is already done by the close routine, so just call that.
  */
-static int ppp_asynctty_hangup(struct tty_struct *tty)
+static void ppp_asynctty_hangup(struct tty_struct *tty)
 {
 	ppp_asynctty_close(tty);
-	return 0;
 }
 
 /*
···
 		/* flush our buffers and the serial port's buffer */
 		if (arg == TCIOFLUSH || arg == TCOFLUSH)
 			ppp_async_flush_output(ap);
-		err = n_tty_ioctl_helper(tty, file, cmd, arg);
+		err = n_tty_ioctl_helper(tty, cmd, arg);
 		break;
 
 	case FIONREAD:
···
 
 	default:
 		/* Try the various mode ioctls */
-		err = tty_mode_ioctl(tty, file, cmd, arg);
+		err = tty_mode_ioctl(tty, cmd, arg);
 	}
 
 	ap_put(ap);

drivers/net/ppp/ppp_synctty.c

···
  * Wait for I/O to driver to complete and unregister PPP channel.
  * This is already done by the close routine, so just call that.
  */
-static int ppp_sync_hangup(struct tty_struct *tty)
+static void ppp_sync_hangup(struct tty_struct *tty)
 {
 	ppp_sync_close(tty);
-	return 0;
 }
 
 /*
···
 		/* flush our buffers and the serial port's buffer */
 		if (arg == TCIOFLUSH || arg == TCOFLUSH)
 			ppp_sync_flush_output(ap);
-		err = n_tty_ioctl_helper(tty, file, cmd, arg);
+		err = n_tty_ioctl_helper(tty, cmd, arg);
 		break;
 
 	case FIONREAD:
···
 		break;
 
 	default:
-		err = tty_mode_ioctl(tty, file, cmd, arg);
+		err = tty_mode_ioctl(tty, cmd, arg);
 		break;
 	}
 

drivers/net/slip/slip.c

···
 	/* This will complete via sl_free_netdev */
 }
 
-static int slip_hangup(struct tty_struct *tty)
+static void slip_hangup(struct tty_struct *tty)
 {
 	slip_close(tty);
-	return 0;
 }
  /************************************************************************
   *			STANDARD SLIP ENCAPSULATION		  	 *
···
 	/* VSV changes end */
 #endif
 	default:
-		return tty_mode_ioctl(tty, file, cmd, arg);
+		return tty_mode_ioctl(tty, cmd, arg);
 	}
 }
 

drivers/rpmsg/rpmsg_core.c

···
 }
 EXPORT_SYMBOL(rpmsg_trysend_offchannel);
 
+/**
+ * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
+ * @ept: the rpmsg endpoint
+ *
+ * This function returns maximum buffer size available for a single outgoing message.
+ *
+ * Return: the maximum transmission size on success and an appropriate error
+ * value on failure.
+ */
+
+ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
+{
+	if (WARN_ON(!ept))
+		return -EINVAL;
+	if (!ept->ops->get_mtu)
+		return -ENOTSUPP;
+
+	return ept->ops->get_mtu(ept);
+}
+EXPORT_SYMBOL(rpmsg_get_mtu);
+
 /*
  * match a rpmsg channel with a channel info struct.
  * this is used to make sure we're not creating rpmsg devices for channels

drivers/rpmsg/rpmsg_internal.h

···
  * @trysendto:		see @rpmsg_trysendto(), optional
  * @trysend_offchannel:	see @rpmsg_trysend_offchannel(), optional
  * @poll:		see @rpmsg_poll(), optional
+ * @get_mtu:		see @rpmsg_get_mtu(), optional
  *
  * Indirection table for the operations that a rpmsg backend should implement.
  * In addition to @destroy_ept, the backend must at least implement @send and
···
 			     void *data, int len);
 	__poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
 			     poll_table *wait);
+	ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);
 };
 
 struct device *rpmsg_find_device(struct device *parent,

drivers/rpmsg/virtio_rpmsg_bus.c

···
 				  int len, u32 dst);
 static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
 					   u32 dst, void *data, int len);
+static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept);
 static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp,
 						   struct rpmsg_channel_info *chinfo);
 
···
 	.trysend = virtio_rpmsg_trysend,
 	.trysendto = virtio_rpmsg_trysendto,
 	.trysend_offchannel = virtio_rpmsg_trysend_offchannel,
+	.get_mtu = virtio_rpmsg_get_mtu,
 };
 
 /**
···
 	struct rpmsg_device *rpdev = ept->rpdev;
 
 	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
+}
+
+static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept)
+{
+	struct rpmsg_device *rpdev = ept->rpdev;
+	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
+
+	return vch->vrp->buf_size - sizeof(struct rpmsg_hdr);
 }
 
 static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,

drivers/tty/Kconfig

···
 
 source "drivers/tty/hvc/Kconfig"
 
+config RPMSG_TTY
+	tristate "RPMSG tty driver"
+	depends on RPMSG
+	help
+	  Say y here to export rpmsg endpoints as tty devices, usually found
+	  in /dev/ttyRPMSGx.
+	  This makes it possible for user-space programs to send and receive
+	  rpmsg messages as a standard tty protocol.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called rpmsg_tty.
+
 endif # TTY
 
 source "drivers/tty/serdev/Kconfig"

drivers/tty/Makefile

···
 obj-$(CONFIG_GOLDFISH_TTY)	+= goldfish.o
 obj-$(CONFIG_MIPS_EJTAG_FDC_TTY) += mips_ejtag_fdc.o
 obj-$(CONFIG_VCC)		+= vcc.o
+obj-$(CONFIG_RPMSG_TTY)		+= rpmsg_tty.o
 
 obj-y += ipwireless/

drivers/tty/hvc/hvc_console.c

···
 #define N_OUTBUF	16
 #define N_INBUF		16
 
-#define __ALIGNED__ __attribute__((__aligned__(sizeof(long))))
+#define __ALIGNED__ __attribute__((__aligned__(L1_CACHE_BYTES)))
 
 static struct tty_driver *hvc_driver;
 static struct task_struct *hvc_task;

drivers/tty/moxa.c

···
 #include <asm/io.h>
 #include <linux/uaccess.h>
 
-#include "moxa.h"
+#define	MOXA			0x400
+#define MOXA_GET_IQUEUE		(MOXA + 1)	/* get input buffered count */
+#define MOXA_GET_OQUEUE		(MOXA + 2)	/* get output buffered count */
+#define MOXA_GETDATACOUNT       (MOXA + 23)
+#define MOXA_GET_IOQUEUE	(MOXA + 27)
+#define MOXA_FLUSH_QUEUE	(MOXA + 28)
+#define MOXA_GETMSTATUS         (MOXA + 65)
+
+/*
+ *    System Configuration
+ */
+
+#define Magic_code	0x404
+
+/*
+ *    for C218 BIOS initialization
+ */
+#define C218_ConfBase	0x800
+#define C218_status	(C218_ConfBase + 0)	/* BIOS running status    */
+#define C218_diag	(C218_ConfBase + 2)	/* diagnostic status      */
+#define C218_key	(C218_ConfBase + 4)	/* WORD (0x218 for C218) */
+#define C218DLoad_len	(C218_ConfBase + 6)	/* WORD           */
+#define C218check_sum	(C218_ConfBase + 8)	/* BYTE           */
+#define C218chksum_ok	(C218_ConfBase + 0x0a)	/* BYTE (1:ok)            */
+#define C218_TestRx	(C218_ConfBase + 0x10)	/* 8 bytes for 8 ports    */
+#define C218_TestTx	(C218_ConfBase + 0x18)	/* 8 bytes for 8 ports    */
+#define C218_RXerr	(C218_ConfBase + 0x20)	/* 8 bytes for 8 ports    */
+#define C218_ErrFlag	(C218_ConfBase + 0x28)	/* 8 bytes for 8 ports    */
+
+#define C218_LoadBuf	0x0F00
+#define C218_KeyCode	0x218
+#define CP204J_KeyCode	0x204
+
+/*
+ *    for C320 BIOS initialization
+ */
+#define C320_ConfBase	0x800
+#define C320_LoadBuf	0x0f00
+#define STS_init	0x05	/* for C320_status        */
+
+#define C320_status	C320_ConfBase + 0	/* BIOS running status    */
+#define C320_diag	C320_ConfBase + 2	/* diagnostic status      */
+#define C320_key	C320_ConfBase + 4	/* WORD (0320H for C320) */
+#define C320DLoad_len	C320_ConfBase + 6	/* WORD           */
+#define C320check_sum	C320_ConfBase + 8	/* WORD           */
+#define C320chksum_ok	C320_ConfBase + 0x0a	/* WORD (1:ok)            */
+#define C320bapi_len	C320_ConfBase + 0x0c	/* WORD           */
+#define C320UART_no	C320_ConfBase + 0x0e	/* WORD           */
+
+#define C320_KeyCode	0x320
+
+#define FixPage_addr	0x0000	/* starting addr of static page  */
+#define DynPage_addr	0x2000	/* starting addr of dynamic page */
+#define C218_start	0x3000	/* starting addr of C218 BIOS prg */
+#define Control_reg	0x1ff0	/* select page and reset control */
+#define HW_reset	0x80
+
+/*
+ *    Function Codes
+ */
+#define FC_CardReset	0x80
+#define FC_ChannelReset 1	/* C320 firmware not supported */
+#define FC_EnableCH	2
+#define FC_DisableCH	3
+#define FC_SetParam	4
+#define FC_SetMode	5
+#define FC_SetRate	6
+#define FC_LineControl	7
+#define FC_LineStatus	8
+#define FC_XmitControl	9
+#define FC_FlushQueue	10
+#define FC_SendBreak	11
+#define FC_StopBreak	12
+#define FC_LoopbackON	13
+#define FC_LoopbackOFF	14
+#define FC_ClrIrqTable	15
+#define FC_SendXon	16
+#define FC_SetTermIrq	17	/* C320 firmware not supported */
+#define FC_SetCntIrq	18	/* C320 firmware not supported */
+#define FC_SetBreakIrq	19
+#define FC_SetLineIrq	20
+#define FC_SetFlowCtl	21
+#define FC_GenIrq	22
+#define FC_InCD180	23
+#define FC_OutCD180	24
+#define FC_InUARTreg	23
+#define FC_OutUARTreg	24
+#define FC_SetXonXoff	25
+#define FC_OutCD180CCR	26
+#define FC_ExtIQueue	27
+#define FC_ExtOQueue	28
+#define FC_ClrLineIrq	29
+#define FC_HWFlowCtl	30
+#define FC_GetClockRate 35
+#define FC_SetBaud	36
+#define FC_SetDataMode  41
+#define FC_GetCCSR      43
+#define FC_GetDataError 45
+#define FC_RxControl	50
+#define FC_ImmSend	51
+#define FC_SetXonState	52
+#define FC_SetXoffState	53
+#define FC_SetRxFIFOTrig 54
+#define FC_SetTxFIFOCnt 55
+#define FC_UnixRate	56
+#define FC_UnixResetTimer 57
+
+#define	RxFIFOTrig1	0
+#define	RxFIFOTrig4	1
+#define	RxFIFOTrig8	2
+#define	RxFIFOTrig14	3
+
+/*
+ *    Dual-Ported RAM
+ */
+#define DRAM_global	0
+#define INT_data	(DRAM_global + 0)
+#define Config_base	(DRAM_global + 0x108)
+
+#define IRQindex	(INT_data + 0)
+#define IRQpending	(INT_data + 4)
+#define IRQtable	(INT_data + 8)
+
+/*
+ *    Interrupt Status
+ */
+#define IntrRx		0x01	/* receiver data O.K.             */
+#define IntrTx		0x02	/* transmit buffer empty  */
+#define IntrFunc	0x04	/* function complete              */
+#define IntrBreak	0x08	/* received break         */
+#define IntrLine	0x10	/* line status change
+				   for transmitter                */
+#define IntrIntr	0x20	/* received INTR code             */
+#define IntrQuit	0x40	/* received QUIT code             */
+#define IntrEOF		0x80	/* received EOF code              */
+
+#define IntrRxTrigger	0x100	/* rx data count reach trigger value */
+#define IntrTxTrigger	0x200	/* tx data count below trigger value */
+
+#define Magic_no	(Config_base + 0)
+#define Card_model_no	(Config_base + 2)
+#define Total_ports	(Config_base + 4)
+#define Module_cnt	(Config_base + 8)
+#define Module_no	(Config_base + 10)
+#define Timer_10ms	(Config_base + 14)
+#define Disable_IRQ	(Config_base + 20)
+#define TMS320_PORT1	(Config_base + 22)
+#define TMS320_PORT2	(Config_base + 24)
+#define TMS320_CLOCK	(Config_base + 26)
+
+/*
+ *    DATA BUFFER in DRAM
+ */
+#define Extern_table	0x400	/* Base address of the external table
+				   (24 words *    64) total 3K bytes
+				   (24 words * 128) total 6K bytes */
+#define Extern_size	0x60	/* 96 bytes                       */
+#define RXrptr		0x00	/* read pointer for RX buffer     */
+#define RXwptr		0x02	/* write pointer for RX buffer    */
+#define TXrptr		0x04	/* read pointer for TX buffer     */
+#define TXwptr		0x06	/* write pointer for TX buffer    */
+#define HostStat	0x08	/* IRQ flag and general flag      */
+#define FlagStat	0x0A
+#define FlowControl	0x0C	/* B7 B6 B5 B4 B3 B2 B1 B0              */
+				/*  x  x  x  x  |  |  |  |            */
+				/*              |  |  |  + CTS flow   */
+				/*              |  |  +--- RTS flow   */
+				/*              |  +------ TX Xon/Xoff */
+				/*              +--------- RX Xon/Xoff */
+#define Break_cnt	0x0E	/* received break count   */
+#define CD180TXirq	0x10	/* if non-0: enable TX irq        */
+#define RX_mask		0x12
+#define TX_mask		0x14
+#define Ofs_rxb		0x16
+#define Ofs_txb		0x18
+#define Page_rxb	0x1A
+#define Page_txb	0x1C
+#define EndPage_rxb	0x1E
+#define EndPage_txb	0x20
+#define Data_error	0x22
+#define RxTrigger	0x28
+#define TxTrigger	0x2a
+
+#define rRXwptr		0x34
+#define Low_water	0x36
+
+#define FuncCode	0x40
+#define FuncArg		0x42
+#define FuncArg1	0x44
+
+#define C218rx_size	0x2000	/* 8K bytes */
+#define C218tx_size	0x8000	/* 32K bytes */
+
+#define C218rx_mask	(C218rx_size - 1)
+#define C218tx_mask	(C218tx_size - 1)
+
+#define C320p8rx_size	0x2000
+#define C320p8tx_size	0x8000
+#define C320p8rx_mask	(C320p8rx_size - 1)
+#define C320p8tx_mask	(C320p8tx_size - 1)
+
+#define C320p16rx_size	0x2000
+#define C320p16tx_size	0x4000
+#define C320p16rx_mask	(C320p16rx_size - 1)
+#define C320p16tx_mask	(C320p16tx_size - 1)
+
+#define C320p24rx_size	0x2000
+#define C320p24tx_size	0x2000
+#define C320p24rx_mask	(C320p24rx_size - 1)
+#define C320p24tx_mask	(C320p24tx_size - 1)
+
+#define C320p32rx_size	0x1000
+#define C320p32tx_size	0x1000
+#define C320p32rx_mask	(C320p32rx_size - 1)
+#define C320p32tx_mask	(C320p32tx_size - 1)
+
+#define Page_size	0x2000U
+#define Page_mask	(Page_size - 1)
+#define C218rx_spage	3
+#define C218tx_spage	4
+#define C218rx_pageno	1
+#define C218tx_pageno	4
+#define C218buf_pageno	5
+
+#define C320p8rx_spage	3
+#define C320p8tx_spage	4
+#define C320p8rx_pgno	1
+#define C320p8tx_pgno	4
+#define C320p8buf_pgno	5
+
+#define C320p16rx_spage 3
+#define C320p16tx_spage 4
+#define C320p16rx_pgno	1
+#define C320p16tx_pgno	2
+#define C320p16buf_pgno 3
+
+#define C320p24rx_spage 3
+#define C320p24tx_spage 4
+#define C320p24rx_pgno	1
+#define C320p24tx_pgno	1
+#define C320p24buf_pgno 2
+
+#define C320p32rx_spage 3
+#define C320p32tx_ofs	C320p32rx_size
+#define C320p32tx_spage 3
+#define C320p32buf_pgno 1
+
+/*
+ *    Host Status
+ */
+#define WakeupRx	0x01
+#define WakeupTx	0x02
+#define WakeupBreak	0x08
+#define WakeupLine	0x10
+#define WakeupIntr	0x20
+#define WakeupQuit	0x40
+#define WakeupEOF	0x80	/* used in VTIME control */
+#define WakeupRxTrigger	0x100
+#define WakeupTxTrigger	0x200
+/*
+ *    Flag status
+ */
+#define Rx_over		0x01
+#define Xoff_state	0x02
+#define Tx_flowOff	0x04
+#define Tx_enable	0x08
+#define CTS_state	0x10
+#define DSR_state	0x20
+#define DCD_state	0x80
+/*
+ *    FlowControl
+ */
+#define CTS_FlowCtl	1
+#define RTS_FlowCtl	2
+#define Tx_FlowCtl	4
+#define Rx_FlowCtl	8
+#define IXM_IXANY	0x10
+
+#define LowWater	128
+
+#define DTR_ON		1
+#define RTS_ON		2
+#define CTS_ON		1
+#define DSR_ON		2
+#define DCD_ON		8
+
+/* mode definition */
+#define	MX_CS8		0x03
+#define	MX_CS7		0x02
+#define	MX_CS6		0x01
+#define	MX_CS5		0x00
+
+#define	MX_STOP1	0x00
+#define	MX_STOP15	0x04
+#define	MX_STOP2	0x08
+
+#define	MX_PARNONE	0x00
+#define	MX_PAREVEN	0x40
+#define	MX_PARODD	0xC0
+#define	MX_PARMARK	0xA0
+#define	MX_PARSPACE	0x20
 
 #define MOXA_VERSION		"6.0k"
 

drivers/tty/moxa.h

···
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef MOXA_H_FILE
-#define MOXA_H_FILE
-
-#define	MOXA		0x400
-#define MOXA_GET_IQUEUE 	(MOXA + 1)	/* get input buffered count */
-#define MOXA_GET_OQUEUE 	(MOXA + 2)	/* get output buffered count */
-#define MOXA_GETDATACOUNT       (MOXA + 23)
-#define MOXA_GET_IOQUEUE	(MOXA + 27)
-#define MOXA_FLUSH_QUEUE	(MOXA + 28)
-#define MOXA_GETMSTATUS         (MOXA + 65)
-
-/*
- *    System Configuration
- */
-
-#define Magic_code	0x404
-
-/*
- *    for C218 BIOS initialization
- */
-#define C218_ConfBase	0x800
-#define C218_status	(C218_ConfBase + 0)	/* BIOS running status    */
-#define C218_diag	(C218_ConfBase + 2)	/* diagnostic status      */
-#define C218_key	(C218_ConfBase + 4)	/* WORD (0x218 for C218) */
-#define C218DLoad_len	(C218_ConfBase + 6)	/* WORD           */
-#define C218check_sum	(C218_ConfBase + 8)	/* BYTE           */
-#define C218chksum_ok	(C218_ConfBase + 0x0a)	/* BYTE (1:ok)            */
-#define C218_TestRx	(C218_ConfBase + 0x10)	/* 8 bytes for 8 ports    */
-#define C218_TestTx	(C218_ConfBase + 0x18)	/* 8 bytes for 8 ports    */
-#define C218_RXerr	(C218_ConfBase + 0x20)	/* 8 bytes for 8 ports    */
-#define C218_ErrFlag	(C218_ConfBase + 0x28)	/* 8 bytes for 8 ports    */
-
-#define C218_LoadBuf	0x0F00
-#define C218_KeyCode	0x218
-#define CP204J_KeyCode	0x204
-
-/*
- *    for C320 BIOS initialization
- */
-#define C320_ConfBase	0x800
-#define C320_LoadBuf	0x0f00
-#define STS_init	0x05	/* for C320_status        */
-
-#define C320_status	C320_ConfBase + 0	/* BIOS running status    */
-#define C320_diag	C320_ConfBase + 2	/* diagnostic status      */
-#define C320_key	C320_ConfBase + 4	/* WORD (0320H for C320) */
-#define C320DLoad_len	C320_ConfBase + 6	/* WORD           */
-#define C320check_sum	C320_ConfBase + 8	/* WORD           */
-#define C320chksum_ok	C320_ConfBase + 0x0a	/* WORD (1:ok)            */
-#define C320bapi_len	C320_ConfBase + 0x0c	/* WORD           */
-#define C320UART_no	C320_ConfBase + 0x0e	/* WORD           */
-
-#define C320_KeyCode	0x320
-
-#define FixPage_addr	0x0000	/* starting addr of static page  */
-#define DynPage_addr	0x2000	/* starting addr of dynamic page */
-#define C218_start	0x3000	/* starting addr of C218 BIOS prg */
-#define Control_reg	0x1ff0	/* select page and reset control */
-#define HW_reset	0x80
-
-/*
- *    Function Codes
- */
-#define FC_CardReset	0x80
-#define FC_ChannelReset 1	/* C320 firmware not supported */
-#define FC_EnableCH	2
-#define FC_DisableCH	3
-#define FC_SetParam	4
-#define FC_SetMode	5
-#define FC_SetRate	6
-#define FC_LineControl	7
-#define FC_LineStatus	8
-#define FC_XmitControl	9
-#define FC_FlushQueue	10
-#define FC_SendBreak	11
-#define FC_StopBreak	12
-#define FC_LoopbackON	13
-#define FC_LoopbackOFF	14
-#define FC_ClrIrqTable	15
-#define FC_SendXon	16
-#define FC_SetTermIrq	17	/* C320 firmware not supported */
-#define FC_SetCntIrq	18	/* C320 firmware not supported */
-#define FC_SetBreakIrq	19
-#define FC_SetLineIrq	20
-#define FC_SetFlowCtl	21
-#define FC_GenIrq	22
-#define FC_InCD180	23
-#define FC_OutCD180	24
-#define FC_InUARTreg	23
-#define FC_OutUARTreg	24
-#define FC_SetXonXoff	25
-#define FC_OutCD180CCR	26
-#define FC_ExtIQueue	27
-#define FC_ExtOQueue	28
-#define FC_ClrLineIrq	29
-#define FC_HWFlowCtl	30
-#define FC_GetClockRate 35
-#define FC_SetBaud	36
-#define FC_SetDataMode  41
-#define FC_GetCCSR      43
-#define FC_GetDataError 45
-#define FC_RxControl	50
-#define FC_ImmSend	51
-#define FC_SetXonState	52
-#define FC_SetXoffState	53
-#define FC_SetRxFIFOTrig 54
-#define FC_SetTxFIFOCnt 55
-#define FC_UnixRate	56
-#define FC_UnixResetTimer 57
-
-#define	RxFIFOTrig1	0
-#define	RxFIFOTrig4	1
-#define	RxFIFOTrig8	2
-#define	RxFIFOTrig14	3
-
-/*
- *    Dual-Ported RAM
- */
-#define DRAM_global	0
-#define INT_data	(DRAM_global + 0)
-#define Config_base	(DRAM_global + 0x108)
-
-#define IRQindex	(INT_data + 0)
-#define IRQpending	(INT_data + 4)
-#define IRQtable	(INT_data + 8)
-
-/*
- *    Interrupt Status
- */
-#define IntrRx		0x01	/* receiver data O.K.             */
-#define IntrTx		0x02	/* transmit buffer empty  */
-#define IntrFunc	0x04	/* function complete              */
-#define IntrBreak	0x08	/* received break         */
-#define IntrLine	0x10	/* line status change
-				   for transmitter                */
-#define IntrIntr	0x20	/* received INTR code             */
-#define IntrQuit	0x40	/* received QUIT code             */
-#define IntrEOF 	0x80	/* received EOF code              */
-
-#define IntrRxTrigger 	0x100	/* rx data count reach trigger value */
-#define IntrTxTrigger 	0x200	/* tx data count below trigger value */
-
-#define Magic_no	(Config_base + 0)
-#define Card_model_no	(Config_base + 2)
-#define Total_ports	(Config_base + 4)
-#define Module_cnt	(Config_base + 8)
-#define Module_no	(Config_base + 10)
-#define Timer_10ms	(Config_base + 14)
-#define Disable_IRQ	(Config_base + 20)
-#define TMS320_PORT1	(Config_base + 22)
-#define TMS320_PORT2	(Config_base + 24)
-#define TMS320_CLOCK	(Config_base + 26)
-
-/*
- *    DATA BUFFER in DRAM
- */
-#define Extern_table	0x400	/* Base address of the external table
-				   (24 words *    64) total 3K bytes
-				   (24 words * 128) total 6K bytes */
-#define Extern_size	0x60	/* 96 bytes                       */
-#define RXrptr		0x00	/* read pointer for RX buffer     */
-#define RXwptr		0x02	/* write pointer for RX buffer    */
-#define TXrptr		0x04	/* read pointer for TX buffer     */
-#define TXwptr		0x06	/* write pointer for TX buffer    */
-#define HostStat	0x08	/* IRQ flag and general flag      */
-#define FlagStat	0x0A
-#define FlowControl	0x0C	/* B7 B6 B5 B4 B3 B2 B1 B0              */
-				/*  x  x  x  x  |  |  |  |            */
-				/*              |  |  |  + CTS flow   */
-				/*              |  |  +--- RTS flow   */
-				/*              |  +------ TX Xon/Xoff */
-				/*              +--------- RX Xon/Xoff */
-#define Break_cnt	0x0E	/* received break count   */
-#define CD180TXirq	0x10	/* if non-0: enable TX irq        */
-#define RX_mask 	0x12
-#define TX_mask 	0x14
-#define Ofs_rxb 	0x16
-#define Ofs_txb 	0x18
-#define Page_rxb	0x1A
-#define Page_txb	0x1C
-#define EndPage_rxb	0x1E
-#define EndPage_txb	0x20
-#define Data_error	0x22
-#define RxTrigger	0x28
-#define TxTrigger	0x2a
-
-#define rRXwptr 	0x34
-#define Low_water	0x36
-
-#define FuncCode	0x40
-#define FuncArg 	0x42
-#define FuncArg1	0x44
-
-#define C218rx_size	0x2000	/* 8K bytes */
-#define C218tx_size	0x8000	/* 32K bytes */
-
-#define C218rx_mask	(C218rx_size - 1)
-#define C218tx_mask	(C218tx_size - 1)
-
-#define C320p8rx_size	0x2000
-#define C320p8tx_size	0x8000
-#define C320p8rx_mask	(C320p8rx_size - 1)
-#define C320p8tx_mask	(C320p8tx_size - 1)
-
-#define C320p16rx_size	0x2000
-#define C320p16tx_size	0x4000
-#define C320p16rx_mask	(C320p16rx_size - 1)
-#define C320p16tx_mask	(C320p16tx_size - 1)
-
-#define C320p24rx_size	0x2000
-#define C320p24tx_size	0x2000
-#define C320p24rx_mask	(C320p24rx_size - 1)
-#define C320p24tx_mask	(C320p24tx_size - 1)
-
-#define C320p32rx_size	0x1000
-#define C320p32tx_size	0x1000
-#define C320p32rx_mask	(C320p32rx_size - 1)
-#define C320p32tx_mask	(C320p32tx_size - 1)
-
-#define Page_size	0x2000U
-#define Page_mask	(Page_size - 1)
-#define C218rx_spage	3
-#define C218tx_spage	4
-#define C218rx_pageno	1
-#define C218tx_pageno	4
-#define C218buf_pageno	5
-
-#define C320p8rx_spage	3
-#define C320p8tx_spage	4
-#define C320p8rx_pgno	1
-#define C320p8tx_pgno	4
-#define C320p8buf_pgno	5
-
-#define C320p16rx_spage 3
-#define C320p16tx_spage 4
-#define C320p16rx_pgno	1
-#define C320p16tx_pgno	2
-#define C320p16buf_pgno 3
-
-#define C320p24rx_spage 3
-#define C320p24tx_spage 4
-#define C320p24rx_pgno	1
-#define C320p24tx_pgno	1
-#define C320p24buf_pgno 2
-
-#define C320p32rx_spage 3
-#define C320p32tx_ofs	C320p32rx_size
-#define C320p32tx_spage 3
-#define C320p32buf_pgno 1
-
-/*
- *    Host Status
- */
-#define WakeupRx	0x01
-#define WakeupTx	0x02
-#define WakeupBreak	0x08
-#define WakeupLine	0x10
-#define WakeupIntr	0x20
-#define WakeupQuit	0x40
-#define WakeupEOF	0x80	/* used in VTIME control */
-#define WakeupRxTrigger	0x100
-#define WakeupTxTrigger	0x200
-/*
- *    Flag status
- */
-#define Rx_over		0x01
-#define Xoff_state	0x02
-#define Tx_flowOff	0x04
-#define Tx_enable	0x08
-#define CTS_state	0x10
-#define DSR_state	0x20
-#define DCD_state	0x80
-/*
- *    FlowControl
- */
-#define CTS_FlowCtl	1
-#define RTS_FlowCtl	2
-#define Tx_FlowCtl	4
-#define Rx_FlowCtl	8
-#define IXM_IXANY	0x10
-
-#define LowWater	128
-
-#define DTR_ON		1
-#define RTS_ON		2
-#define CTS_ON		1
-#define DSR_ON		2
-#define DCD_ON		8
-
-/* mode definition */
-#define	MX_CS8		0x03
-#define	MX_CS7		0x02
-#define	MX_CS6		0x01
-#define	MX_CS5		0x00
-
-#define	MX_STOP1	0x00
-#define	MX_STOP15	0x04
-#define	MX_STOP2	0x08
-
-#define	MX_PARNONE	0x00
-#define	MX_PAREVEN	0x40
-#define	MX_PARODD	0xC0
-#define	MX_PARMARK	0xA0
-#define	MX_PARSPACE	0x20
-
-#endif

drivers/tty/mxser.c

···
 	unsigned char x_char;	/* xon/xoff character */
 	u8 IER;			/* Interrupt Enable Register */
 	u8 MCR;			/* Modem control register */
+	u8 FCR;			/* FIFO control register */
 
-	unsigned char ldisc_stop_rx;
+	bool ldisc_stop_rx;
 
 	struct async_icount icount; /* kernel counters for 4 input interrupts */
 	unsigned int timeout;
···
  * This routine is called to set the UART divisor registers to match
  * the specified baud rate for a serial port.
  */
-static void mxser_change_speed(struct tty_struct *tty)
+static void mxser_change_speed(struct tty_struct *tty, struct ktermios *old_termios)
 {
 	struct mxser_port *info = tty->driver_data;
-	unsigned cflag, cval, fcr;
+	unsigned cflag, cval;
 
 	cflag = tty->termios.c_cflag;
 
-	mxser_set_baud(tty, tty_get_baud_rate(tty));
+	if (mxser_set_baud(tty, tty_get_baud_rate(tty))) {
+		/* Use previous rate on a failure */
+		if (old_termios) {
+			speed_t baud = tty_termios_baud_rate(old_termios);
+			tty_encode_baud_rate(tty, baud, baud);
+		}
+	}
 
 	/* byte size and parity */
 	switch (cflag & CSIZE) {
···
 	if (cflag & CMSPAR)
 		cval |= UART_LCR_SPAR;
 
-	if ((info->type == PORT_8250) || (info->type == PORT_16450)) {
-		if (info->board->must_hwid) {
-			fcr = UART_FCR_ENABLE_FIFO;
-			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
-			mxser_set_must_fifo_value(info);
-		} else
-			fcr = 0;
-	} else {
-		fcr = UART_FCR_ENABLE_FIFO;
-		if (info->board->must_hwid) {
-			fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
-			mxser_set_must_fifo_value(info);
-		} else {
-			switch (info->rx_high_water) {
-			case 1:
-				fcr |= UART_FCR_TRIGGER_1;
-				break;
-			case 4:
-				fcr |= UART_FCR_TRIGGER_4;
-				break;
-			case 8:
-				fcr |= UART_FCR_TRIGGER_8;
-				break;
-			default:
-				fcr |= UART_FCR_TRIGGER_14;
-				break;
-			}
+	info->FCR = 0;
+	if (info->board->must_hwid) {
+		info->FCR |= UART_FCR_ENABLE_FIFO |
+			MOXA_MUST_FCR_GDA_MODE_ENABLE;
+		mxser_set_must_fifo_value(info);
+	} else if (info->type != PORT_8250 && info->type != PORT_16450) {
+		info->FCR |= UART_FCR_ENABLE_FIFO;
+		switch (info->rx_high_water) {
+		case 1:
+			info->FCR |= UART_FCR_TRIGGER_1;
+			break;
+		case 4:
+			info->FCR |= UART_FCR_TRIGGER_4;
+			break;
+		case 8:
+			info->FCR |= UART_FCR_TRIGGER_8;
+			break;
+		default:
+			info->FCR |= UART_FCR_TRIGGER_14;
+			break;
 		}
 	}
 
···
 	}
 
 
-	outb(fcr, info->ioaddr + UART_FCR);	/* set fcr */
+	outb(info->FCR, info->ioaddr + UART_FCR);
 	outb(cval, info->ioaddr + UART_LCR);
 }
 
···
 		mxser_handle_cts(tty, port, status);
 }
 
+static void mxser_disable_and_clear_FIFO(struct mxser_port *info)
+{
+	u8 fcr = UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT;
+
+	if (info->board->must_hwid)
+		fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
+
+	outb(fcr, info->ioaddr + UART_FCR);
+}
+
 static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
 {
 	struct mxser_port *info = container_of(port, struct mxser_port, port);
···
 	 * Clear the FIFO buffers and disable them
 	 * (they will be reenabled in mxser_change_speed())
 	 */
-	if (info->board->must_hwid)
-		outb((UART_FCR_CLEAR_RCVR |
-			UART_FCR_CLEAR_XMIT |
-			MOXA_MUST_FCR_GDA_MODE_ENABLE), info->ioaddr + UART_FCR);
-	else
-		outb((UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
-			info->ioaddr + UART_FCR);
+	mxser_disable_and_clear_FIFO(info);
 
 	/*
 	 * At this point there's no way the LSR could still be 0xFF;
···
 	/*
 	 * and set the speed of the serial port
 	 */
-	mxser_change_speed(tty);
+	mxser_change_speed(tty, NULL);
 	spin_unlock_irqrestore(&info->slock, flags);
 
 	return 0;
···
 	outb(0x00, info->ioaddr + UART_IER);
 
 	/* clear Rx/Tx FIFO's */
-	if (info->board->must_hwid)
-		outb(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT |
-				MOXA_MUST_FCR_GDA_MODE_ENABLE,
-				info->ioaddr + UART_FCR);
-	else
-		outb(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
-			info->ioaddr + UART_FCR);
+	mxser_disable_and_clear_FIFO(info);
 
 	/* read data port to reset things */
 	(void) inb(info->ioaddr + UART_RX);
···
 static void mxser_flush_buffer(struct tty_struct *tty)
 {
 	struct mxser_port *info = tty->driver_data;
-	char fcr;
 	unsigned long flags;
 
 
 	spin_lock_irqsave(&info->slock, flags);
 	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 
-	fcr = inb(info->ioaddr + UART_FCR);
-	outb((fcr | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
+	outb(info->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
 		info->ioaddr + UART_FCR);
-	outb(fcr, info->ioaddr + UART_FCR);
 
 	spin_unlock_irqrestore(&info->slock, flags);
 
···
 	if (tty_port_initialized(port)) {
 		if (old_speed != (port->flags & ASYNC_SPD_MASK)) {
 			spin_lock_irqsave(&info->slock, sl_flags);
-			mxser_change_speed(tty);
+			mxser_change_speed(tty, NULL);
 			spin_unlock_irqrestore(&info->slock, sl_flags);
 		}
 	} else {
···
 {
 	struct mxser_port *info = tty->driver_data;
 
-	info->ldisc_stop_rx = 1;
+	info->ldisc_stop_rx = true;
 	if (I_IXOFF(tty)) {
 		if (info->board->must_hwid) {
 			info->IER &= ~MOXA_MUST_RECV_ISR;
···
 	struct mxser_port *info = tty->driver_data;
 
 	/* startrx */
-	info->ldisc_stop_rx = 0;
+	info->ldisc_stop_rx = false;
 	if (I_IXOFF(tty)) {
 		if (info->x_char)
 			info->x_char = 0;
···
 	unsigned long flags;
 
 	spin_lock_irqsave(&info->slock, flags);
-	mxser_change_speed(tty);
+	mxser_change_speed(tty, old_termios);
 	spin_unlock_irqrestore(&info->slock, flags);
 
 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
···
 
 	if (hwid == MOXA_OTHER_UART)
 		return false;
-	if (status & UART_LSR_BRK_ERROR_BITS)
-		return false;
-	if (hwid == MOXA_MUST_MU860_HWID && (status & MOXA_MUST_LSR_RERR))
-		return false;
-	if (status & MOXA_MUST_LSR_RERR)
+	if (status & (UART_LSR_BRK_ERROR_BITS | MOXA_MUST_LSR_RERR))
 		return false;
 
 	gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
···
 
 		ch = inb(port->ioaddr + UART_RX);
 		if (hwid && (status & UART_LSR_OE))
-			outb(UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
-					MOXA_MUST_FCR_GDA_MODE_ENABLE,
+			outb(port->FCR | UART_FCR_CLEAR_RCVR,
 					port->ioaddr + UART_FCR);
 		status &= port->read_status_mask;
 		if (status & port->ignore_status_mask) {
···
 	tty = tty_port_tty_get(&port->port);
 	if (!tty || port->closing || !tty_port_initialized(&port->port)) {
 		status = inb(port->ioaddr + UART_LSR);
-		outb(MOXA_MUST_FCR_GDA_MODE_ENABLE | UART_FCR_ENABLE_FIFO |
-				UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+		outb(port->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
 				port->ioaddr + UART_FCR);
 		inb(port->ioaddr + UART_MSR);
 
···
 		tty_port_init(&info->port);
 		info->port.ops = &mxser_port_ops;
 		info->board = brd;
-		info->ldisc_stop_rx = 0;
+		info->ldisc_stop_rx = false;
 
 		/* Enhance mode enabled here */
 		if (brd->must_hwid != MOXA_OTHER_UART)

drivers/tty/n_gsm.c

···
 
 static struct tty_driver *gsm_tty_driver;
 
+/* Save dlci open address */
+static int addr_open[256] = { 0 };
+/* Save dlci open count */
+static int addr_cnt;
 /*
  *	This section of the driver logic implements the GSM encodings
  *	both the basic and the 'advanced'. Reliable transport is not
···
 		return;
 	}
 	gsmld_output(gsm, cbuf, len);
+	if (!gsm->initiator) {
+		cr = cr & gsm->initiator;
+		control = control & ~PF;
+	}
 	gsm_print_packet("-->", addr, cr, control, NULL, 0);
 }
 
···
 
 static inline void gsm_response(struct gsm_mux *gsm, int addr, int control)
 {
-	gsm_send(gsm, addr, 0, control);
+	gsm_send(gsm, addr, 1, control);
 }
 
 /**
···
 			print_hex_dump_bytes("gsm_data_kick: ",
 					     DUMP_PREFIX_OFFSET,
 					     gsm->txframe, len);
-		if (gsmld_output(gsm, gsm->txframe, len) < 0)
+		if (gsmld_output(gsm, gsm->txframe, len) <= 0)
 			break;
 		/* FIXME: Can eliminate one SOF in many more cases */
 		gsm->tx_bytes -= msg->len;
···
 }
 
 static void gsm_dlci_begin_close(struct gsm_dlci *dlci);
+static void gsm_dlci_close(struct gsm_dlci *dlci);
 
 /**
  *	gsm_control_message	-	DLCI 0 control processing
···
 {
 	u8 buf[1];
 	unsigned long flags;
+	struct gsm_dlci *dlci;
+	int i;
+	int address;
 
 	switch (command) {
 	case CMD_CLD: {
-		struct gsm_dlci *dlci = gsm->dlci[0];
+		if (addr_cnt > 0) {
+			for (i = 0; i < addr_cnt; i++) {
+				address = addr_open[i];
+				dlci = gsm->dlci[address];
+				gsm_dlci_close(dlci);
+				addr_open[i] = 0;
+			}
+		}
 		/* Modem wishes to close down */
+		dlci = gsm->dlci[0];
 		if (dlci) {
 			dlci->dead = true;
 			gsm->dead = true;
-			gsm_dlci_begin_close(dlci);
+			gsm_dlci_close(dlci);
+			addr_cnt = 0;
+			gsm_response(gsm, 0, UA|PF);
 		}
 		}
 		break;
···
 		kfifo_reset(&dlci->fifo);
 	} else
 		dlci->gsm->dead = true;
+	/* Unregister gsmtty driver,report gsmtty dev remove uevent for user */
+	tty_unregister_device(gsm_tty_driver, dlci->addr);
 	wake_up(&dlci->gsm->event);
 	/* A DLCI 0 close is a MUX termination so we need to kick that
 	   back to userspace somehow */
···
 	dlci->state = DLCI_OPEN;
 	if (debug & 8)
 		pr_debug("DLCI %d goes open.\n", dlci->addr);
+	/* Register gsmtty driver,report gsmtty dev add uevent for user */
+	tty_register_device(gsm_tty_driver, dlci->addr, NULL);
 	wake_up(&dlci->gsm->event);
 }
 
···
 	struct gsm_dlci *dlci;
 	u8 cr;
 	int address;
+	int i, j, k, address_tmp;
 	/* We have to sneak a look at the packet body to do the FCS.
 	   A somewhat layering violation in the spec */
 
···
 
 	switch (gsm->control) {
 	case SABM|PF:
-		if (cr == 0)
+		if (cr == 1)
 			goto invalid;
 		if (dlci == NULL)
 			dlci = gsm_dlci_alloc(gsm, address);
 		if (dlci == NULL)
 			return;
 		if (dlci->dead)
-			gsm_response(gsm, address, DM);
+			gsm_response(gsm, address, DM|PF);
 		else {
-			gsm_response(gsm, address, UA);
+			gsm_response(gsm, address, UA|PF);
 			gsm_dlci_open(dlci);
+			/* Save dlci open address */
+			if (address) {
+				addr_open[addr_cnt] = address;
+				addr_cnt++;
+			}
 		}
 		break;
 	case DISC|PF:
-		if (cr == 0)
+		if (cr == 1)
 			goto invalid;
 		if (dlci == NULL || dlci->state == DLCI_CLOSED) {
-			gsm_response(gsm, address, DM);
+			gsm_response(gsm, address, DM|PF);
 			return;
 		}
 		/* Real close complete */
-		gsm_response(gsm, address, UA);
-		gsm_dlci_close(dlci);
+		if (!address) {
+			if (addr_cnt > 0) {
+				for (i = 0; i < addr_cnt; i++) {
+					address = addr_open[i];
+					dlci = gsm->dlci[address];
+					gsm_dlci_close(dlci);
+					addr_open[i] = 0;
+				}
+			}
+			dlci = gsm->dlci[0];
+			gsm_dlci_close(dlci);
+			addr_cnt = 0;
+			gsm_response(gsm, 0, UA|PF);
+		} else {
+			gsm_response(gsm, address, UA|PF);
+			gsm_dlci_close(dlci);
+			/* clear dlci address */
+			for (j = 0; j < addr_cnt; j++) {
+				address_tmp = addr_open[j];
+				if (address_tmp == address) {
+					for (k = j; k < addr_cnt; k++)
+						addr_open[k] = addr_open[k+1];
+					addr_cnt--;
+					break;
+				}
+			}
+		}
 		break;
 	case UA:
 	case UA|PF:
···
 	 * configuration
 	 */
 
-	if (need_close || need_restart) {
+	if (gsm->initiator && (need_close || need_restart)) {
 		int ret;
 
 		ret = gsm_disconnect(gsm);
···
 	if (debug & 4)
 		print_hex_dump_bytes("gsmld_output: ", DUMP_PREFIX_OFFSET,
 				     data, len);
-	gsm->tty->ops->write(gsm->tty, data, len);
-	return len;
+	return gsm->tty->ops->write(gsm->tty, data, len);
 }
 
 /**
···
 	else {
 		/* Don't register device 0 - this is the control channel and not
 		   a usable tty interface */
-		base = mux_num_to_base(gsm); /* Base for this MUX */
-		for (i = 1; i < NUM_DLCI; i++) {
-			struct device *dev;
+		if (gsm->initiator) {
+			base = mux_num_to_base(gsm); /* Base for this MUX */
+			for (i = 1; i < NUM_DLCI; i++) {
+				struct device *dev;
 
-			dev = tty_register_device(gsm_tty_driver,
+				dev = tty_register_device(gsm_tty_driver,
 							base + i, NULL);
-			if (IS_ERR(dev)) {
-				for (i--; i >= 1; i--)
-					tty_unregister_device(gsm_tty_driver,
-								base + i);
-				return PTR_ERR(dev);
+				if (IS_ERR(dev)) {
+					for (i--; i >= 1; i--)
+						tty_unregister_device(gsm_tty_driver,
+									base + i);
+					return PTR_ERR(dev);
+				}
 			}
 		}
 	}
···
 	int i;
 
 	WARN_ON(tty != gsm->tty);
-	for (i = 1; i < NUM_DLCI; i++)
-		tty_unregister_device(gsm_tty_driver, base + i);
+	if (gsm->initiator) {
+		for (i = 1; i < NUM_DLCI; i++)
+			tty_unregister_device(gsm_tty_driver, base + i);
+	}
 	gsm_cleanup_mux(gsm);
 	tty_kref_put(gsm->tty);
 	gsm->tty = NULL;
···
 		base = mux_num_to_base(gsm);
 		return put_user(base + 1, (__u32 __user *)arg);
 	default:
-		return n_tty_ioctl_helper(tty, file, cmd, arg);
+		return n_tty_ioctl_helper(tty, cmd, arg);
 	}
 }
 
···
 {
 	struct gsm_dlci *dlci = tty->driver_data;
 	struct tty_port *port = &dlci->port;
+	struct gsm_mux *gsm = dlci->gsm;
 
 	port->count++;
 	tty_port_tty_set(port, tty);
···
 	   a DM straight back. This is ok as that will have caused a hangup */
 	tty_port_set_initialized(port, 1);
 	/* Start sending off SABM messages */
-	gsm_dlci_begin_open(dlci);
+	if (gsm->initiator)
+		gsm_dlci_begin_open(dlci);
 	/* And wait for virtual carrier */
 	return tty_port_block_til_ready(port, tty, filp);
 }

drivers/tty/n_hdlc.c

···
 		fallthrough;	/* to default */
 
 	default:
-		error = n_tty_ioctl_helper(tty, file, cmd, arg);
+		error = n_tty_ioctl_helper(tty, cmd, arg);
 		break;
 	}
 	return error;

drivers/tty/n_tty.c

···
 		up_write(&tty->termios_rwsem);
 		return put_user(retval, (unsigned int __user *) arg);
 	default:
-		return n_tty_ioctl_helper(tty, file, cmd, arg);
+		return n_tty_ioctl_helper(tty, cmd, arg);
 	}
 }
 
···
 {
 	*ops = n_tty_ops;
 	ops->owner = NULL;
-	ops->flags = 0;
 }
 EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
 

drivers/tty/rpmsg_tty.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 STMicroelectronics - All Rights Reserved
+ *
+ * The rpmsg tty driver implements serial communication on the RPMsg bus to makes
+ * possible for user-space programs to send and receive rpmsg messages as a standard
+ * tty protocol.
+ *
+ * The remote processor can instantiate a new tty by requesting a "rpmsg-tty" RPMsg service.
+ * The "rpmsg-tty" service is directly used for data exchange. No flow control is implemented yet.
+ */
+
+#define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/rpmsg.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define RPMSG_TTY_NAME	"ttyRPMSG"
+#define MAX_TTY_RPMSG	32
+
+static DEFINE_IDR(tty_idr);	/* tty instance id */
+static DEFINE_MUTEX(idr_lock);	/* protects tty_idr */
+
+static struct tty_driver *rpmsg_tty_driver;
+
+struct rpmsg_tty_port {
+	struct tty_port		port;	 /* TTY port data */
+	int			id;	 /* TTY rpmsg index */
+	struct rpmsg_device	*rpdev;	 /* rpmsg device */
+};
+
+static int rpmsg_tty_cb(struct rpmsg_device *rpdev, void *data, int len, void *priv, u32 src)
+{
+	struct rpmsg_tty_port *cport = dev_get_drvdata(&rpdev->dev);
+	int copied;
+
+	if (!len)
+		return -EINVAL;
+	copied = tty_insert_flip_string(&cport->port, data, len);
+	if (copied != len)
+		dev_err_ratelimited(&rpdev->dev, "Trunc buffer: available space is %d\n", copied);
+	tty_flip_buffer_push(&cport->port);
+
+	return 0;
+}
+
+static int rpmsg_tty_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct rpmsg_tty_port *cport = idr_find(&tty_idr, tty->index);
+
+	tty->driver_data = cport;
+
+	return tty_port_install(&cport->port, driver, tty);
+}
+
+static int rpmsg_tty_open(struct tty_struct *tty, struct file *filp)
+{
+	return tty_port_open(tty->port, tty, filp);
+}
+
+static void rpmsg_tty_close(struct tty_struct *tty, struct file *filp)
+{
+	return tty_port_close(tty->port, tty, filp);
+}
+
+static int rpmsg_tty_write(struct tty_struct *tty, const u8 *buf, int len)
+{
+	struct rpmsg_tty_port *cport = tty->driver_data;
+	struct rpmsg_device *rpdev;
+	int msg_max_size, msg_size;
+	int ret;
+
+	rpdev = cport->rpdev;
+
+	msg_max_size = rpmsg_get_mtu(rpdev->ept);
+	if (msg_max_size < 0)
+		return msg_max_size;
+
+	msg_size = min(len, msg_max_size);
+
+	/*
+	 * Use rpmsg_trysend instead of rpmsg_send to send the message so the caller is not
+	 * hung until a rpmsg buffer is available. In such case rpmsg_trysend returns -ENOMEM.
+	 */
+	ret = rpmsg_trysend(rpdev->ept, (void *)buf, msg_size);
+	if (ret) {
+		dev_dbg_ratelimited(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
+		return ret;
+	}
+
+	return msg_size;
+}
+
+static unsigned int rpmsg_tty_write_room(struct tty_struct *tty)
+{
+	struct rpmsg_tty_port *cport = tty->driver_data;
+	int size;
+
+	size = rpmsg_get_mtu(cport->rpdev->ept);
+	if (size < 0)
+		return 0;
+
+	return size;
+}
+
+static const struct tty_operations rpmsg_tty_ops = {
+	.install	= rpmsg_tty_install,
+	.open		= rpmsg_tty_open,
+	.close		= rpmsg_tty_close,
+	.write		= rpmsg_tty_write,
+	.write_room	= rpmsg_tty_write_room,
+};
+
+static struct rpmsg_tty_port *rpmsg_tty_alloc_cport(void)
+{
+	struct rpmsg_tty_port *cport;
+	int ret;
+
+	cport = kzalloc(sizeof(*cport), GFP_KERNEL);
+	if (!cport)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_lock(&idr_lock);
+	ret = idr_alloc(&tty_idr, cport, 0, MAX_TTY_RPMSG, GFP_KERNEL);
+	mutex_unlock(&idr_lock);
+
+	if (ret < 0) {
+		kfree(cport);
+		return ERR_PTR(ret);
+	}
+
+	cport->id = ret;
+
+	return cport;
+}
+
+static void rpmsg_tty_release_cport(struct rpmsg_tty_port *cport)
+{
+	mutex_lock(&idr_lock);
+	idr_remove(&tty_idr, cport->id);
+	mutex_unlock(&idr_lock);
+
+	kfree(cport);
+}
+
+static const struct tty_port_operations rpmsg_tty_port_ops = { };
+
+static int rpmsg_tty_probe(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_tty_port *cport;
+	struct device *dev = &rpdev->dev;
+	struct device *tty_dev;
+	int ret;
+
+	cport = rpmsg_tty_alloc_cport();
+	if (IS_ERR(cport))
+		return dev_err_probe(dev, PTR_ERR(cport), "Failed to alloc tty port\n");
+
+	tty_port_init(&cport->port);
+	cport->port.ops = &rpmsg_tty_port_ops;
+
+	tty_dev = tty_port_register_device(&cport->port, rpmsg_tty_driver,
+					   cport->id, dev);
+	if (IS_ERR(tty_dev)) {
+		ret = dev_err_probe(dev, PTR_ERR(tty_dev), "Failed to register tty port\n");
+		goto err_destroy;
+	}
+
+	cport->rpdev = rpdev;
+
+	dev_set_drvdata(dev, cport);
+
+	dev_dbg(dev, "New channel: 0x%x -> 0x%x: " RPMSG_TTY_NAME "%d\n",
+		rpdev->src, rpdev->dst, cport->id);
+
+	return 0;
+
+err_destroy:
+	tty_port_destroy(&cport->port);
+	rpmsg_tty_release_cport(cport);
+
+	return ret;
+}
+
+static void rpmsg_tty_remove(struct rpmsg_device *rpdev)
+{
+	struct rpmsg_tty_port *cport = dev_get_drvdata(&rpdev->dev);
+
+	dev_dbg(&rpdev->dev, "Removing rpmsg tty device %d\n", cport->id);
+
+	/* User hang up to release the tty */
+	if (tty_port_initialized(&cport->port))
+		tty_port_tty_hangup(&cport->port, false);
+
+	tty_unregister_device(rpmsg_tty_driver, cport->id);
+
+	tty_port_destroy(&cport->port);
+	rpmsg_tty_release_cport(cport);
+}
+
+static struct rpmsg_device_id rpmsg_driver_tty_id_table[] = {
+	{ .name	= "rpmsg-tty" },
+	{ },
+};
+MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_tty_id_table);
+
+static struct rpmsg_driver rpmsg_tty_rpmsg_drv = {
+	.drv.name	= KBUILD_MODNAME,
+	.id_table	= rpmsg_driver_tty_id_table,
+	.probe		= rpmsg_tty_probe,
+	.callback	= rpmsg_tty_cb,
+	.remove		= rpmsg_tty_remove,
+};
+
+static int __init rpmsg_tty_init(void)
+{
+	int ret;
+
+	rpmsg_tty_driver = tty_alloc_driver(MAX_TTY_RPMSG, TTY_DRIVER_REAL_RAW |
+					    TTY_DRIVER_DYNAMIC_DEV);
+	if (IS_ERR(rpmsg_tty_driver))
+		return PTR_ERR(rpmsg_tty_driver);
+
+	rpmsg_tty_driver->driver_name = "rpmsg_tty";
+	rpmsg_tty_driver->name = RPMSG_TTY_NAME;
+	rpmsg_tty_driver->major = 0;
+	rpmsg_tty_driver->type = TTY_DRIVER_TYPE_CONSOLE;
+
+	/* Disable unused mode by default */
+	rpmsg_tty_driver->init_termios = tty_std_termios;
+	rpmsg_tty_driver->init_termios.c_lflag &= ~(ECHO | ICANON);
+	rpmsg_tty_driver->init_termios.c_oflag &= ~(OPOST | ONLCR);
+
+	tty_set_operations(rpmsg_tty_driver, &rpmsg_tty_ops);
+
+	ret = tty_register_driver(rpmsg_tty_driver);
+	if (ret < 0) {
+		pr_err("Couldn't install driver: %d\n", ret);
+		goto error_put;
+	}
+
+	ret = register_rpmsg_driver(&rpmsg_tty_rpmsg_drv);
+	if (ret < 0) {
+		pr_err("Couldn't register driver: %d\n", ret);
+		goto error_unregister;
+	}
+
+	return 0;
+
+error_unregister:
+	tty_unregister_driver(rpmsg_tty_driver);
+
+error_put:
+	tty_driver_kref_put(rpmsg_tty_driver);
+
+	return ret;
+}
+
+static void __exit rpmsg_tty_exit(void)
+{
+	unregister_rpmsg_driver(&rpmsg_tty_rpmsg_drv);
+	tty_unregister_driver(rpmsg_tty_driver);
+	tty_driver_kref_put(rpmsg_tty_driver);
+	idr_destroy(&tty_idr);
+}
+
+module_init(rpmsg_tty_init);
+module_exit(rpmsg_tty_exit);
+
+MODULE_AUTHOR("Arnaud Pouliquen <[e-mail]>");
+MODULE_DESCRIPTION("remote processor messaging tty driver");
+MODULE_LICENSE("GPL v2");

drivers/tty/serial/8250/8250_dw.c

···
 	rate = clk_round_rate(d->clk, newrate);
 	if (rate > 0) {
 		/*
-		 * Premilinary set the uartclk to the new clock rate so the
-		 * clock update event handler caused by the clk_set_rate()
-		 * calling wouldn't actually update the UART divisor since
-		 * we about to do this anyway.
+		 * Note that any clock-notifer worker will block in
+		 * serial8250_update_uartclk() until we are done.
 		 */
-		swap(p->uartclk, rate);
 		ret = clk_set_rate(d->clk, newrate);
-		if (ret)
-			swap(p->uartclk, rate);
+		if (!ret)
+			p->uartclk = rate;
 	}
 	clk_prepare_enable(d->clk);
 
-	p->status &= ~UPSTAT_AUTOCTS;
-	if (termios->c_cflag & CRTSCTS)
-		p->status |= UPSTAT_AUTOCTS;
-
-	serial8250_do_set_termios(p, termios, old);
+	dw8250_do_set_termios(p, termios, old);
 }
 
 static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
···
 
 static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 {
-	if (p->dev->of_node) {
-		struct device_node *np = p->dev->of_node;
+	struct device_node *np = p->dev->of_node;
+
+	if (np) {
 		int id;
 
 		/* get index of serial line, if found in DT aliases */
···
 			data->skip_autocfg = true;
 		}
 #endif
-		if (of_device_is_big_endian(p->dev->of_node)) {
+
+		if (of_device_is_big_endian(np)) {
 			p->iotype = UPIO_MEM32BE;
 			p->serial_in = dw8250_serial_in32be;
 			p->serial_out = dw8250_serial_out32be;
 		}
+
 		if (of_device_is_compatible(np, "marvell,armada-38x-uart"))
 			p->serial_out = dw8250_serial_out38x;
 
···
 		.name		= "dw-apb-uart",
 		.pm		= &dw8250_pm_ops,
 		.of_match_table	= dw8250_of_match,
-		.acpi_match_table = ACPI_PTR(dw8250_acpi_match),
+		.acpi_match_table = dw8250_acpi_match,
 	},
 	.probe			= dw8250_probe,
 	.remove			= dw8250_remove,

drivers/tty/serial/8250/8250_dwlib.c

···
 	serial8250_do_set_divisor(p, baud, quot, quot_frac);
 }
 
+void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, struct ktermios *old)
+{
+	p->status &= ~UPSTAT_AUTOCTS;
+	if (termios->c_cflag & CRTSCTS)
+		p->status |= UPSTAT_AUTOCTS;
+
+	serial8250_do_set_termios(p, termios, old);
+}
+EXPORT_SYMBOL_GPL(dw8250_do_set_termios);
+
 void dw8250_setup_port(struct uart_port *p)
 {
 	struct uart_8250_port *up = up_to_u8250p(p);

drivers/tty/serial/8250/8250_dwlib.h

···
 	u8			dlf_size;
 };
 
+void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, struct ktermios *old);
 void dw8250_setup_port(struct uart_port *p);

drivers/tty/serial/8250/8250_fsl.c

···
 
 #include "8250.h"
 
-struct fsl8250_data {
-	int	line;
-};
-
 int fsl8250_handle_irq(struct uart_port *port)
 {
 	unsigned char lsr, orig_lsr;
···
 EXPORT_SYMBOL_GPL(fsl8250_handle_irq);
 
 #ifdef CONFIG_ACPI
+struct fsl8250_data {
+	int	line;
+};
+
 static int fsl8250_acpi_probe(struct platform_device *pdev)
 {
 	struct fsl8250_data *data;

drivers/tty/serial/8250/8250_lpss.c

···
 	reg |= BYT_PRV_CLK_EN | BYT_PRV_CLK_UPDATE;
 	writel(reg, p->membase + BYT_PRV_CLK);
 
-	p->status &= ~UPSTAT_AUTOCTS;
-	if (termios->c_cflag & CRTSCTS)
-		p->status |= UPSTAT_AUTOCTS;
-
-	serial8250_do_set_termios(p, termios, old);
+	dw8250_do_set_termios(p, termios, old);
 }
 
 static unsigned int byt_get_mctrl(struct uart_port *port)
···
 	 * matching with the registered General Purpose DMA controllers.
 	 */
 	up->dma = dma;
+
+	port->set_termios = dw8250_do_set_termios;
+
 	return 0;
 }
 

drivers/tty/serial/8250/8250_pci.c

···
 
 static void moan_device(const char *str, struct pci_dev *dev)
 {
-	dev_err(&dev->dev,
-	       "%s: %s\n"
+	pci_err(dev, "%s\n"
 	       "Please send the output of lspci -vv, this\n"
 	       "message (0x%04x,0x%04x,0x%04x,0x%04x), the\n"
 	       "manufacturer and name of serial board or\n"
 	       "modem board to <[e-mail]>.\n",
-	       pci_name(dev), str, dev->vendor, dev->device,
+	       str, dev->vendor, dev->device,
 	       dev->subsystem_vendor, dev->subsystem_device);
 }
 
···
 	/* is firmware started? */
 	pci_read_config_dword(dev, 0x44, &oldval);
 	if (oldval == 0x00001000L) { /* RESET value */
-		dev_dbg(&dev->dev, "Local i960 firmware missing\n");
+		pci_dbg(dev, "Local i960 firmware missing\n");
 		return -ENODEV;
 	}
 	return 0;
···
 
 	if (type == 0x1000)
 		return pci_siig10x_init(dev);
-	else if (type == 0x2000)
+	if (type == 0x2000)
 		return pci_siig20x_init(dev);
 
 	moan_device("Unknown SIIG card", dev);
···
 	 * (0,2,3,5,6: serial only -- 7,8,9: serial + parallel)
 	 */
 	if ((dev->subsystem_device & 0x00f0) >= 0x70) {
-		dev_info(&dev->dev,
-			"ignoring Timedia subdevice %04x for parport_serial\n",
-			dev->subsystem_device);
+		pci_info(dev, "ignoring Timedia subdevice %04x for parport_serial\n",
+			 dev->subsystem_device);
 		return -ENODEV;
 	}
 
···
 		bar = 3 * idx;
 
 		return setup_port(priv, port, bar, 0, board->reg_shift);
-	} else {
-		return pci_default_setup(priv, board, port, idx);
 	}
+
+	return pci_default_setup(priv, board, port, idx);
 }
 
 /* the 99xx series comes with a range of device IDs and a variety
···
 		if (sub_serports > 0)
 			return sub_serports;
 
-		dev_err(&dev->dev,
-			"NetMos/Mostech serial driver ignoring port on ambiguous config.\n");
+		pci_err(dev, "NetMos/Mostech serial driver ignoring port on ambiguous config.\n");
 		return 0;
 	}
 
···
 /* enable IO_Space bit */
 #define ITE_887x_POSIO_ENABLE		(1 << 31)
 
+/* inta_addr are the configuration addresses of the ITE */
+static const short inta_addr[] = { 0x2a0, 0x2c0, 0x220, 0x240, 0x1e0, 0x200, 0x280 };
 static int pci_ite887x_init(struct pci_dev *dev)
 {
-	/* inta_addr are the configuration addresses of the ITE */
-	static const short inta_addr[] = { 0x2a0, 0x2c0, 0x220, 0x240, 0x1e0,
-							0x200, 0x280, 0 };
 	int ret, i, type;
 	struct resource *iobase = NULL;
 	u32 miscr, uartbar, ioport;
 
 	/* search for the base-ioport */
-	i = 0;
-	while (inta_addr[i] && iobase == NULL) {
+	for (i = 0; i < ARRAY_SIZE(inta_addr); i++) {
 		iobase = request_region(inta_addr[i], ITE_887x_IOSIZE,
 								"ite887x");
 		if (iobase != NULL) {
···
 				break;
 			}
 			release_region(iobase->start, ITE_887x_IOSIZE);
-			iobase = NULL;
 		}
-		i++;
 	}
 
-	if (!inta_addr[i]) {
-		dev_err(&dev->dev, "ite887x: could not find iobase\n");
+	if (i == ARRAY_SIZE(inta_addr)) {
+		pci_err(dev, "could not find iobase\n");
 		return -ENODEV;
 	}
 
···
 	/* EndRun device */
 	if (deviceID == 0x07000200) {
 		number_uarts = ioread8(p + 4);
-		dev_dbg(&dev->dev,
-			"%d ports detected on EndRun PCI Express device\n",
-			number_uarts);
+		pci_dbg(dev, "%d ports detected on EndRun PCI Express device\n", number_uarts);
 	}
 	pci_iounmap(dev, p);
 	return number_uarts;
···
 	/* Tornado device */
 	if (deviceID == 0x07000200) {
 		number_uarts = ioread8(p + 4);
-		dev_dbg(&dev->dev,
-			"%d ports detected on Oxford PCI Express device\n",
-			number_uarts);
+		pci_dbg(dev, "%d ports detected on Oxford PCI Express device\n", number_uarts);
 	}
 	pci_iounmap(dev, p);
 	return number_uarts;
···
 	port->bugs |= UART_BUG_PARITY;
 	return pci_default_setup(priv, board, port, idx);
 }
-
-/* Quatech devices have their own extra interface features */
-
-struct quatech_feature {
-	u16 devid;
-	bool amcc;
-};
 
 #define QPCR_TEST_FOR1		0x3F
 #define QPCR_TEST_GET1		0x00
···
 #define QOPR_CLOCK_X8		0x0003
 #define QOPR_CLOCK_RATE_MASK	0x0003
 
-
-static struct quatech_feature quatech_cards[] = {
-	{ PCI_DEVICE_ID_QUATECH_QSC100,   1 },
-	{ PCI_DEVICE_ID_QUATECH_DSC100,   1 },
-	{ PCI_DEVICE_ID_QUATECH_DSC100E,  0 },
-	{ PCI_DEVICE_ID_QUATECH_DSC200,   1 },
-	{ PCI_DEVICE_ID_QUATECH_DSC200E,  0 },
-	{ PCI_DEVICE_ID_QUATECH_ESC100D,  1 },
-	{ PCI_DEVICE_ID_QUATECH_ESC100M,  1 },
-	{ PCI_DEVICE_ID_QUATECH_QSCP100,  1 },
-	{ PCI_DEVICE_ID_QUATECH_DSCP100,  1 },
-	{ PCI_DEVICE_ID_QUATECH_QSCP200,  1 },
-	{ PCI_DEVICE_ID_QUATECH_DSCP200,  1 },
-	{ PCI_DEVICE_ID_QUATECH_ESCLP100, 0 },
-	{ PCI_DEVICE_ID_QUATECH_QSCLP100, 0 },
-	{ PCI_DEVICE_ID_QUATECH_DSCLP100, 0 },
-	{ PCI_DEVICE_ID_QUATECH_SSCLP100, 0 },
-	{ PCI_DEVICE_ID_QUATECH_QSCLP200, 0 },
-	{ PCI_DEVICE_ID_QUATECH_DSCLP200, 0 },
-	{ PCI_DEVICE_ID_QUATECH_SSCLP200, 0 },
-	{ PCI_DEVICE_ID_QUATECH_SPPXP_100, 0 },
+/* Quatech devices have their own extra interface features */
+static struct pci_device_id quatech_cards[] = {
+	{ PCI_DEVICE_DATA(QUATECH, QSC100,   1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC100,   1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC100E,  0) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC200,   1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSC200E,  0) },
+	{ PCI_DEVICE_DATA(QUATECH, ESC100D,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, ESC100M,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCP100,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCP100,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCP200,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCP200,  1) },
+	{ PCI_DEVICE_DATA(QUATECH, ESCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, SSCLP100, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, QSCLP200, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, DSCLP200, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, SSCLP200, 0) },
+	{ PCI_DEVICE_DATA(QUATECH, SPPXP_100, 0) },
 	{ 0, }
-};
-
-static int pci_quatech_amcc(u16 devid)
-{
-	struct quatech_feature *qf = &quatech_cards[0];
-	while (qf->devid) {
-		if (qf->devid == devid)
-			return qf->amcc;
-		qf++;
-	}
-	pr_err("quatech: unknown port type '0x%04X'.\n", devid);
-	return 0;
 };
 
 static int pci_quatech_rqopr(struct uart_8250_port *port)
···
 
 static int pci_quatech_init(struct pci_dev *dev)
 {
-	if (pci_quatech_amcc(dev->device)) {
+	const struct pci_device_id *match;
+	bool amcc = false;
+
+	match = pci_match_id(quatech_cards, dev);
+	if (match)
+		amcc = match->driver_data;
+	else
+		pci_err(dev, "unknown port type '0x%04X'.\n", dev->device);
+
+	if (amcc) {
 		unsigned long base = pci_resource_start(dev, 0);
 		if (base) {
 			u32 tmp;
···
 	port->port.uartclk = pci_quatech_clock(port);
 	/* For now just warn about RS422 */
 	if (pci_quatech_rs422(port))
-		pr_warn("quatech: software control of RS422 features not currently supported.\n");
+		pci_warn(priv->dev, "software control of RS422 features not currently supported.\n");
 	return pci_default_setup(priv, board, port, idx);
-}
-
-static void pci_quatech_exit(struct pci_dev *dev)
-{
 }
 
 static int pci_default_setup(struct serial_private *priv,
···
 	/* Get the io address from configuration space */
 	pci_read_config_word(pdev, config_base + 4, &iobase);
 
-	dev_dbg(&pdev->dev, "%s: idx=%d iobase=0x%x", __func__, idx, iobase);
+	pci_dbg(pdev, "idx=%d iobase=0x%x", idx, iobase);
 
 	port->port.iotype = UPIO_PORT;
 	port->port.iobase = iobase;
···
 			struct uart_8250_port *port, int idx)
 {
 	port->port.quirks |= UPQ_NO_TXEN_TEST;
-	dev_dbg(&priv->dev->dev,
+	pci_dbg(priv->dev,
 		"serial8250: skipping TxEn test for device [%04x:%04x] subsystem [%04x:%04x]\n",
 		priv->dev->vendor, priv->dev->device,
 		priv->dev->subsystem_vendor, priv->dev->subsystem_device);
···
 		.subdevice	= PCI_ANY_ID,
 		.init		= pci_quatech_init,
 		.setup		= pci_quatech_setup,
-		.exit		= pci_quatech_exit,
 	},
 	/*
 	 * Panacom
···
 			nr_ports = rc;
 	}
 
-	priv = kzalloc(sizeof(struct serial_private) +
-		       sizeof(unsigned int) * nr_ports,
-		       GFP_KERNEL);
+	priv = kzalloc(struct_size(priv, line, nr_ports), GFP_KERNEL);
 	if (!priv) {
 		priv = ERR_PTR(-ENOMEM);
 		goto err_deinit;
···
 		uart.port.irq = 0;
 	} else {
 		if (pci_match_id(pci_use_msi, dev)) {
-			dev_dbg(&dev->dev, "Using MSI(-X) interrupts\n");
+			pci_dbg(dev, "Using MSI(-X) interrupts\n");
 			pci_set_master(dev);
 			uart.port.flags &= ~UPF_SHARE_IRQ;
 			rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_ALL_TYPES);
 		} else {
-			dev_dbg(&dev->dev, "Using legacy interrupts\n");
+			pci_dbg(dev, "Using legacy interrupts\n");
 			rc = pci_alloc_irq_vectors(dev, 1, 1, PCI_IRQ_LEGACY);
 		}
 		if (rc < 0) {
···
 		if (quirk->setup(priv, board, &uart, i))
 			break;
 
-		dev_dbg(&dev->dev, "Setup PCI port: port %lx, irq %d, type %d\n",
+		pci_dbg(dev, "Setup PCI port: port %lx, irq %d, type %d\n",
 			uart.port.iobase, uart.port.irq, uart.port.iotype);
 
 		priv->line[i] = serial8250_register_8250_port(&uart);
 		if (priv->line[i] < 0) {
-			dev_err(&dev->dev,
+			pci_err(dev,
 				"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
 				uart.port.iobase, uart.port.irq,
 				uart.port.iotype, priv->line[i]);
···
 	}
 
 	if (ent->driver_data >= ARRAY_SIZE(pci_boards)) {
-		dev_err(&dev->dev, "invalid driver_data: %ld\n",
-			ent->driver_data);
+		pci_err(dev, "invalid driver_data: %ld\n", ent->driver_data);
 		return -EINVAL;
 	}
 
···
 		err = pci_enable_device(pdev);
 		/* FIXME: We cannot simply error out here */
 		if (err)
-			dev_err(dev, "Unable to re-enable ports, trying to continue.\n");
+			pci_err(pdev, "Unable to re-enable ports, trying to continue.\n");
 		pciserial_resume_ports(priv);
 	}
 	return 0;

drivers/tty/serial/8250/8250_pnp.c

···
 	{	"BRI1400",		0	},
 	/* Boca 33.6 Kbps Internal FD34FSVD */
 	{	"BRI3400",		0	},
-	/* Boca 33.6 Kbps Internal FD34FSVD */
-	{	"BRI0A49",		0	},
-	/* Best Data Products Inc. Smart One 336F PnP Modem */
-	{	"BDP3336",		0	},
 	/* Computer Peripherals Inc */
 	/* EuroViVa CommCenter-33.6 SP PnP */
 	{	"CPI4050",		0	},

drivers/tty/serial/8250/8250_port.c

···
 	up->tx_loadsz = uart_config[port->type].tx_loadsz;
 
 	if (port->type == PORT_UNKNOWN)
-		goto out_lock;
+		goto out_unlock;
 
 	/*
 	 * Reset the UART.
···
 	else
 		serial_out(up, UART_IER, 0);
 
-out_lock:
+out_unlock:
 	spin_unlock_irqrestore(&port->lock, flags);
 
 	/*
···
 void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
+	struct tty_port *tport = &port->state->port;
 	unsigned int baud, quot, frac = 0;
 	struct ktermios *termios;
+	struct tty_struct *tty;
 	unsigned long flags;
 
-	mutex_lock(&port->state->port.mutex);
+	tty = tty_port_tty_get(tport);
+	if (!tty) {
+		mutex_lock(&tport->mutex);
+		port->uartclk = uartclk;
+		mutex_unlock(&tport->mutex);
+		return;
+	}
+
+	down_write(&tty->termios_rwsem);
+	mutex_lock(&tport->mutex);
 
 	if (port->uartclk == uartclk)
-		goto out_lock;
+		goto out_unlock;
 
 	port->uartclk = uartclk;
 
-	if (!tty_port_initialized(&port->state->port))
-		goto out_lock;
+	if (!tty_port_initialized(tport))
+		goto out_unlock;
 
-	termios = &port->state->port.tty->termios;
+	termios = &tty->termios;
 
 	baud = serial8250_get_baud_rate(port, termios, NULL);
 	quot = serial8250_get_divisor(port, baud, &frac);
···
 	spin_unlock_irqrestore(&port->lock, flags);
 	serial8250_rpm_put(up);
 
-out_lock:
-	mutex_unlock(&port->state->port.mutex);
+out_unlock:
+	mutex_unlock(&tport->mutex);
+	up_write(&tty->termios_rwsem);
+	tty_kref_put(tty);
 }
 EXPORT_SYMBOL_GPL(serial8250_update_uartclk);
 

drivers/tty/serial/8250/Kconfig

···
 config SERIAL_8250_EM
 	tristate "Support for Emma Mobile integrated serial port"
 	depends on SERIAL_8250 && HAVE_CLK
-	depends on ARM || COMPILE_TEST
+	depends on (ARM && ARCH_RENESAS) || COMPILE_TEST
 	help
 	  Selecting this option will add support for the integrated serial
 	  port hardware found on the Emma Mobile line of processors.

drivers/tty/serial/Kconfig

···
 	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_APPLE || COMPILE_TEST
 	select SERIAL_CORE
 	help
-	  Support for the on-chip UARTs on the Samsung S3C24XX series CPUs,
-	  providing /dev/ttySAC0, 1 and 2 (note, some machines may not
-	  provide all of these ports, depending on how the serial port
-	  pins are configured.
+	  Support for the on-chip UARTs on the Samsung
+	  S3C24xx/S3C64xx/S5Pv210/Exynos and Apple M1 SoCs, providing
+	  /dev/ttySAC0, 1 and 2 (note, some machines may not provide all of
+	  these ports, depending on how the serial port pins are configured.
+	  Choose Y/M here only if you build for such SoC.
 
 config SERIAL_SAMSUNG_UARTS_4
 	bool

drivers/tty/serial/atmel_serial.c

···
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
 
 	switch (state) {
-	case 0:
+	case UART_PM_STATE_ON:
 		/*
 		 * Enable the peripheral clock for this serial port.
 		 * This is called on uart_open() or a resume event.
···
 		/* re-enable interrupts if we disabled some on suspend */
 		atmel_uart_writel(port, ATMEL_US_IER, atmel_port->backup_imr);
 		break;
-	case 3:
+	case UART_PM_STATE_OFF:
 		/* Back up the interrupt mask and disable all interrupts */
 		atmel_port->backup_imr = atmel_uart_readl(port, ATMEL_US_IMR);
 		atmel_uart_writel(port, ATMEL_US_IDR, -1);

drivers/tty/serial/cpm_uart/cpm_uart_core.c

···
 	cpm_uart_early_write(pinfo, ch, 1, false);
 }
 
+#ifdef CONFIG_SERIAL_CPM_CONSOLE
 static struct uart_port *udbg_port;
 
 static void udbg_cpm_putc(char c)
···
 		cpu_relax();
 	return c;
 }
+#endif /* CONFIG_SERIAL_CPM_CONSOLE */
 
 #endif /* CONFIG_CONSOLE_POLL */
 

drivers/tty/serial/imx.c

···
  * If the port was already initialised (eg, by a boot loader),
  * try to determine the current setup.
  */
-static void __init
+static void
 imx_uart_console_get_options(struct imx_port *sport, int *baud,
 			     int *parity, int *bits)
 {
···
 	}
 }
 
-static int __init
+static int
 imx_uart_console_setup(struct console *co, char *options)
 {
 	struct imx_port *sport;
···
 	return retval;
 }
 
+static int
+imx_uart_console_exit(struct console *co)
+{
+	struct imx_port *sport = imx_uart_ports[co->index];
+
+	clk_disable_unprepare(sport->clk_per);
+	clk_disable_unprepare(sport->clk_ipg);
+
+	return 0;
+}
+
 static struct uart_driver imx_uart_uart_driver;
 static struct console imx_uart_console = {
 	.name		= DEV_NAME,
 	.write		= imx_uart_console_write,
 	.device		= uart_console_device,
 	.setup		= imx_uart_console_setup,
+	.exit		= imx_uart_console_exit,
 	.flags		= CON_PRINTBUFFER,
 	.index		= -1,
 	.data		= &imx_uart_uart_driver,

drivers/tty/serial/max310x.c

···
 	return ret;
 }
 
-static int max310x_remove(struct device *dev)
+static void max310x_remove(struct device *dev)
 {
 	struct max310x_port *s = dev_get_drvdata(dev);
 	int i;
···
 	}
 
 	clk_disable_unprepare(s->clk);
-
-	return 0;
 }
 
 static const struct of_device_id __maybe_unused max310x_dt_ids[] = {
···
 
 static int max310x_spi_remove(struct spi_device *spi)
 {
-	return max310x_remove(&spi->dev);
+	max310x_remove(&spi->dev);
+	return 0;
 }
 
 static const struct spi_device_id max310x_id_table[] = {

drivers/tty/serial/samsung_tty.c

···
 struct s3c24xx_uart_info {
 	char			*name;
 	enum s3c24xx_port_type	type;
-	unsigned int		has_usi;
+	bool			has_usi;
 	unsigned int		port_type;
 	unsigned int		fifosize;
 	unsigned long		rx_fifomask;
···
 #endif
 
 #if defined(CONFIG_ARCH_EXYNOS)
-#define EXYNOS_COMMON_SERIAL_DRV_DATA_USI(_has_usi)		\
+#define EXYNOS_COMMON_SERIAL_DRV_DATA(_has_usi)			\
 	.info = &(struct s3c24xx_uart_info) {			\
 		.name		= "Samsung Exynos UART",	\
 		.type		= TYPE_S3C6400,			\
···
 		.has_fracval	= 1,				\
 	}							\
 
-#define EXYNOS_COMMON_SERIAL_DRV_DATA				\
-	EXYNOS_COMMON_SERIAL_DRV_DATA_USI(0)
-
 static struct s3c24xx_serial_drv_data exynos4210_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA,
+	EXYNOS_COMMON_SERIAL_DRV_DATA(false),
 	.fifosize = { 256, 64, 16, 16 },
 };
 
 static struct s3c24xx_serial_drv_data exynos5433_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA,
+	EXYNOS_COMMON_SERIAL_DRV_DATA(false),
 	.fifosize = { 64, 256, 16, 256 },
 };
 
 static struct s3c24xx_serial_drv_data exynos850_serial_drv_data = {
-	EXYNOS_COMMON_SERIAL_DRV_DATA_USI(1),
+	EXYNOS_COMMON_SERIAL_DRV_DATA(true),
 	.fifosize = { 256, 64, 64, 64 },
 };
 

drivers/tty/serial/sc16is7xx.c

···
 	return ret;
 }
 
-static int sc16is7xx_remove(struct device *dev)
+static void sc16is7xx_remove(struct device *dev)
 {
 	struct sc16is7xx_port *s = dev_get_drvdata(dev);
 	int i;
···
 	kthread_stop(s->kworker_task);
 
 	clk_disable_unprepare(s->clk);
-
-	return 0;
 }
 
 static const struct of_device_id __maybe_unused sc16is7xx_dt_ids[] = {
···
 
 static int sc16is7xx_spi_remove(struct spi_device *spi)
 {
-	return sc16is7xx_remove(&spi->dev);
+	sc16is7xx_remove(&spi->dev);
+
+	return 0;
 }
 
 static const struct spi_device_id sc16is7xx_spi_id_table[] = {
···
 
 static int sc16is7xx_i2c_remove(struct i2c_client *client)
 {
-	return sc16is7xx_remove(&client->dev);
+	sc16is7xx_remove(&client->dev);
+
+	return 0;
 }
 
 static const struct i2c_device_id sc16is7xx_i2c_id_table[] = {

drivers/tty/serial/serial_core.c

···
 	if (retval == 0) {
 		if (uart_console(uport) && uport->cons->cflag) {
 			tty->termios.c_cflag = uport->cons->cflag;
+			tty->termios.c_ispeed = uport->cons->ispeed;
+			tty->termios.c_ospeed = uport->cons->ospeed;
 			uport->cons->cflag = 0;
+			uport->cons->ispeed = 0;
+			uport->cons->ospeed = 0;
 		}
 		/*
 		 * Initialise the hardware port settings.
···
 		/*
 		 * Turn off DTR and RTS early.
 		 */
-		if (uport && uart_console(uport) && tty)
+		if (uport && uart_console(uport) && tty) {
 			uport->cons->cflag = tty->termios.c_cflag;
+			uport->cons->ispeed = tty->termios.c_ispeed;
+			uport->cons->ospeed = tty->termios.c_ospeed;
+		}
 
 		if (!tty || C_HUPCL(tty))
 			uart_port_dtr_rts(uport, 0);
···
 	 * Allow the setting of the UART parameters with a NULL console
 	 * too:
 	 */
-	if (co)
+	if (co) {
 		co->cflag = termios.c_cflag;
+		co->ispeed = termios.c_ispeed;
+		co->ospeed = termios.c_ospeed;
+	}
 
 	return 0;
 }
···
 		 */
 		memset(&termios, 0, sizeof(struct ktermios));
 		termios.c_cflag = uport->cons->cflag;
+		termios.c_ispeed = uport->cons->ispeed;
+		termios.c_ospeed = uport->cons->ospeed;
 
 		/*
 		 * If that's unset, use the tty termios setting.

drivers/tty/serial/sifive.c

···
 
 static void __ssp_remove_console_port(struct sifive_serial_port *ssp)
 {
-	sifive_serial_console_ports[ssp->port.line] = 0;
+	sifive_serial_console_ports[ssp->port.line] = NULL;
 }
 
 #define SIFIVE_SERIAL_CONSOLE	(&sifive_serial_console)

drivers/tty/serial/stm32-usart.c

···
 	return uart_get_rs485_mode(port);
 }
 
-static int stm32_usart_pending_rx(struct uart_port *port, u32 *sr,
-				  int *last_res, bool threaded)
+static bool stm32_usart_rx_dma_enabled(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-	enum dma_status status;
-	struct dma_tx_state state;
 
-	*sr = readl_relaxed(port->membase + ofs->isr);
+	if (!stm32_port->rx_ch)
+		return false;
 
-	if (threaded && stm32_port->rx_ch) {
-		status = dmaengine_tx_status(stm32_port->rx_ch,
-					     stm32_port->rx_ch->cookie,
-					     &state);
-		if (status == DMA_IN_PROGRESS && (*last_res != state.residue))
-			return 1;
-		else
-			return 0;
-	} else if (*sr & USART_SR_RXNE) {
-		return 1;
-	}
-	return 0;
+	return !!(readl_relaxed(port->membase + ofs->cr3) & USART_CR3_DMAR);
 }
 
-static unsigned long stm32_usart_get_char(struct uart_port *port, u32 *sr,
-					  int *last_res)
+/* Return true when data is pending (in pio mode), and false when no data is pending. */
+static bool stm32_usart_pending_rx_pio(struct uart_port *port, u32 *sr)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	*sr = readl_relaxed(port->membase + ofs->isr);
+	/* Get pending characters in RDR or FIFO */
+	if (*sr & USART_SR_RXNE) {
+		/* Get all pending characters from the RDR or the FIFO when using interrupts */
+		if (!stm32_usart_rx_dma_enabled(port))
+			return true;
+
+		/* Handle only RX data errors when using DMA */
+		if (*sr & USART_SR_ERR_MASK)
+			return true;
+	}
+
+	return false;
+}
+
+static unsigned long stm32_usart_get_char_pio(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	unsigned long c;
 
-	if (stm32_port->rx_ch) {
-		c = stm32_port->rx_buf[RX_BUF_L - (*last_res)--];
-		if ((*last_res) == 0)
-			*last_res = RX_BUF_L;
-	} else {
-		c = readl_relaxed(port->membase + ofs->rdr);
-		/* apply RDR data mask */
-		c &= stm32_port->rdr_mask;
-	}
+	c = readl_relaxed(port->membase + ofs->rdr);
+	/* Apply RDR data mask */
+	c &= stm32_port->rdr_mask;
 
 	return c;
 }
 
-static void stm32_usart_receive_chars(struct uart_port *port, bool threaded)
+static unsigned int stm32_usart_receive_chars_pio(struct uart_port *port)
 {
-	struct tty_port *tport = &port->state->port;
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	unsigned long c;
+	unsigned int size = 0;
 	u32 sr;
 	char flag;
 
-	spin_lock(&port->lock);
-
-	while (stm32_usart_pending_rx(port, &sr, &stm32_port->last_res,
-				      threaded)) {
+	while (stm32_usart_pending_rx_pio(port, &sr)) {
 		sr |= USART_SR_DUMMY_RX;
 		flag = TTY_NORMAL;
 
···
 			writel_relaxed(sr & USART_SR_ERR_MASK,
 				       port->membase + ofs->icr);
 
-		c = stm32_usart_get_char(port, &sr, &stm32_port->last_res);
+		c = stm32_usart_get_char_pio(port);
 		port->icount.rx++;
+		size++;
 		if (sr & USART_SR_ERR_MASK) {
 			if (sr & USART_SR_ORE) {
 				port->icount.overrun++;
···
 		uart_insert_char(port, sr, USART_SR_ORE, c, flag);
 	}
 
-	uart_unlock_and_check_sysrq(port);
+	return size;
+}
 
-	tty_flip_buffer_push(tport);
+static void stm32_usart_push_buffer_dma(struct uart_port *port, unsigned int dma_size)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct tty_port *ttyport = &stm32_port->port.state->port;
+	unsigned char *dma_start;
+	int dma_count, i;
+
+	dma_start = stm32_port->rx_buf + (RX_BUF_L - stm32_port->last_res);
+
+	/*
+	 * Apply rdr_mask on buffer in order to mask parity bit.
+	 * This loop is useless in cs8 mode because DMA copies only
+	 * 8 bits and already ignores parity bit.
+	 */
+	if (!(stm32_port->rdr_mask == (BIT(8) - 1)))
+		for (i = 0; i < dma_size; i++)
+			*(dma_start + i) &= stm32_port->rdr_mask;
+
+	dma_count = tty_insert_flip_string(ttyport, dma_start, dma_size);
+	port->icount.rx += dma_count;
+	if (dma_count != dma_size)
+		port->icount.buf_overrun++;
+	stm32_port->last_res -= dma_count;
+	if (stm32_port->last_res == 0)
+		stm32_port->last_res = RX_BUF_L;
+}
+
+static unsigned int stm32_usart_receive_chars_dma(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	unsigned int dma_size, size = 0;
+
+	/* DMA buffer is configured in cyclic mode and handles the rollback of the buffer. */
+	if (stm32_port->rx_dma_state.residue > stm32_port->last_res) {
+		/* Conditional first part: from last_res to end of DMA buffer */
+		dma_size = stm32_port->last_res;
+		stm32_usart_push_buffer_dma(port, dma_size);
+		size = dma_size;
+	}
+
+	dma_size = stm32_port->last_res - stm32_port->rx_dma_state.residue;
+	stm32_usart_push_buffer_dma(port, dma_size);
+	size += dma_size;
+
+	return size;
+}
+
+static unsigned int stm32_usart_receive_chars(struct uart_port *port, bool force_dma_flush)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	enum dma_status rx_dma_status;
+	u32 sr;
+	unsigned int size = 0;
+
+	if (stm32_usart_rx_dma_enabled(port) || force_dma_flush) {
+		rx_dma_status = dmaengine_tx_status(stm32_port->rx_ch,
+						    stm32_port->rx_ch->cookie,
+						    &stm32_port->rx_dma_state);
+		if (rx_dma_status == DMA_IN_PROGRESS) {
+			/* Empty DMA buffer */
+			size = stm32_usart_receive_chars_dma(port);
+			sr = readl_relaxed(port->membase + ofs->isr);
+			if (sr & USART_SR_ERR_MASK) {
+				/* Disable DMA request line */
+				stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+
+				/* Switch to PIO mode to handle the errors */
+				size += stm32_usart_receive_chars_pio(port);
+
+				/* Switch back to DMA mode */
+				stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAR);
+			}
+		} else {
+			/* Disable RX DMA */
+			dmaengine_terminate_async(stm32_port->rx_ch);
+			stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+			/* Fall back to interrupt mode */
+			dev_dbg(port->dev, "DMA error, fallback to irq mode\n");
+			size = stm32_usart_receive_chars_pio(port);
+		}
+	} else {
+		size = stm32_usart_receive_chars_pio(port);
+	}
+
+	return size;
 }
 
 static void stm32_usart_tx_dma_complete(void *arg)
···
 		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_TXFTIE);
 	else
 		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_TXEIE);
+}
+
+static void stm32_usart_rx_dma_complete(void *arg)
+{
+	struct uart_port *port = arg;
+	struct tty_port *tport = &port->state->port;
+	unsigned int size;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	size = stm32_usart_receive_chars(port, false);
+	uart_unlock_and_check_sysrq_irqrestore(port, flags);
+	if (size)
+		tty_flip_buffer_push(tport);
 }
 
 static void stm32_usart_tx_interrupt_disable(struct uart_port *port)
···
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	u32 sr;
+	unsigned int size;
 
 	sr = readl_relaxed(port->membase + ofs->isr);
 
···
 			pm_wakeup_event(tport->tty->dev, 0);
 	}
 
-	if ((sr & USART_SR_RXNE) && !(stm32_port->rx_ch))
-		stm32_usart_receive_chars(port, false);
+	/*
+	 * rx errors in dma mode has to be handled ASAP to avoid overrun as the DMA request
+	 * line has been masked by HW and rx data are stacking in FIFO.
+	 */
+	if (!stm32_port->throttled) {
+		if (((sr & USART_SR_RXNE) && !stm32_usart_rx_dma_enabled(port)) ||
+		    ((sr & USART_SR_ERR_MASK) && stm32_usart_rx_dma_enabled(port))) {
+			spin_lock(&port->lock);
+			size = stm32_usart_receive_chars(port, false);
+			uart_unlock_and_check_sysrq(port);
+			if (size)
+				tty_flip_buffer_push(tport);
+		}
+	}
 
 	if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch)) {
 		spin_lock(&port->lock);
···
 		spin_unlock(&port->lock);
 	}
 
-	if (stm32_port->rx_ch)
+	if (stm32_usart_rx_dma_enabled(port))
 		return IRQ_WAKE_THREAD;
 	else
 		return IRQ_HANDLED;
···
 static irqreturn_t stm32_usart_threaded_interrupt(int irq, void *ptr)
 {
 	struct uart_port *port = ptr;
+	struct tty_port *tport = &port->state->port;
 	struct stm32_port *stm32_port = to_stm32_port(port);
+	unsigned int size;
+	unsigned long flags;
 
-	if (stm32_port->rx_ch)
-		stm32_usart_receive_chars(port, true);
+	/* Receiver timeout irq for DMA RX */
+	if (!stm32_port->throttled) {
+		spin_lock_irqsave(&port->lock, flags);
+		size = stm32_usart_receive_chars(port, false);
+		uart_unlock_and_check_sysrq_irqrestore(port, flags);
+		if (size)
+			tty_flip_buffer_push(tport);
+	}
 
 	return IRQ_HANDLED;
 }
···
 	unsigned long flags;
 
 	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Disable DMA request line if enabled, so the RX data gets queued into the FIFO.
+	 * Hardware flow control is triggered when RX FIFO is full.
+	 */
+	if (stm32_usart_rx_dma_enabled(port))
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+
 	stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
 	if (stm32_port->cr3_irq)
 		stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
 
+	stm32_port->throttled = true;
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
···
 	if (stm32_port->cr3_irq)
 		stm32_usart_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
 
+	/*
+	 * Switch back to DMA mode (re-enable DMA request line).
+	 * Hardware flow control is stopped when FIFO is not full any more.
+	 */
+	if (stm32_port->rx_ch)
+		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAR);
+
+	stm32_port->throttled = false;
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
···
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
+	/* Disable DMA request line. */
+	if (stm32_port->rx_ch)
+		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+
 	stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
 	if (stm32_port->cr3_irq)
 		stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
···
 /* Handle breaks - ignored by us */
 static void stm32_usart_break_ctl(struct uart_port *port, int break_state)
 {
+}
+
+static int stm32_usart_start_rx_dma_cyclic(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	struct dma_async_tx_descriptor *desc;
+	int ret;
+
+	stm32_port->last_res = RX_BUF_L;
+	/* Prepare a DMA cyclic transaction */
+	desc = dmaengine_prep_dma_cyclic(stm32_port->rx_ch,
+					 stm32_port->rx_dma_buf,
+					 RX_BUF_L, RX_BUF_P,
+					 DMA_DEV_TO_MEM,
+					 DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(port->dev, "rx dma prep cyclic failed\n");
+		return -ENODEV;
+	}
+
+	desc->callback = stm32_usart_rx_dma_complete;
+	desc->callback_param = port;
+
+	/* Push current DMA transaction in the pending queue */
+	ret = dma_submit_error(dmaengine_submit(desc));
+	if (ret) {
+		dmaengine_terminate_sync(stm32_port->rx_ch);
+		return ret;
+	}
+
+	/* Issue pending DMA requests */
+	dma_async_issue_pending(stm32_port->rx_ch);
+
+	/*
+	 * DMA request line not re-enabled at resume when port is throttled.
+	 * It will be re-enabled by unthrottle ops.
+	 */
+	if (!stm32_port->throttled)
+		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_DMAR);
+
+	return 0;
 }
 
 static int stm32_usart_startup(struct uart_port *port)
···
 	/* RX FIFO Flush */
 	if (ofs->rqr != UNDEF_REG)
 		writel_relaxed(USART_RQR_RXFRQ, port->membase + ofs->rqr);
+
+	if (stm32_port->rx_ch) {
+		ret = stm32_usart_start_rx_dma_cyclic(port);
+		if (ret) {
+			free_irq(port->irq, port);
+			return ret;
+		}
+	}
 
 	/* RX enabling */
 	val = stm32_port->cr1_irq | USART_CR1_RE | BIT(cfg->uart_enable_bit);
···
 	/* Send the TC error message only when ISR_TC is not set */
 	if (ret)
 		dev_err(port->dev, "Transmission is not complete\n");
+
+	/* Disable RX DMA. */
+	if (stm32_port->rx_ch)
+		dmaengine_terminate_async(stm32_port->rx_ch);
 
 	/* flush RX & TX FIFO */
 	if (ofs->rqr != UNDEF_REG)
···
 		stm32_port->cr1_irq = USART_CR1_RTOIE;
 		writel_relaxed(bits, port->membase + ofs->rtor);
 		cr2 |= USART_CR2_RTOEN;
-		/* Not using dma, enable fifo threshold irq */
-		if (!stm32_port->rx_ch)
-			stm32_port->cr3_irq =  USART_CR3_RXFTIE;
+		/*
+		 * Enable fifo threshold irq in two cases, either when there is no DMA, or when
+		 * wake up over usart, from low power until the DMA gets re-enabled by resume.
+		 */
+		stm32_port->cr3_irq =  USART_CR3_RXFTIE;
 	}
 
 	cr1 |= stm32_port->cr1_irq;
···
 	if ((termios->c_cflag & CREAD) == 0)
 		port->ignore_status_mask |= USART_SR_DUMMY_RX;
 
-	if (stm32_port->rx_ch)
+	if (stm32_port->rx_ch) {
+		/*
+		 * Setup DMA to collect only valid data and enable error irqs.
+		 * This also enables break reception when using DMA.
+		 */
+		cr1 |= USART_CR1_PEIE;
+		cr3 |= USART_CR3_EIE;
 		cr3 |= USART_CR3_DMAR;
+		cr3 |= USART_CR3_DDRE;
+	}
 
 	if (rs485conf->flags & SER_RS485_ENABLED) {
 		stm32_usart_config_reg_rs485(&cr1, &cr3,
···
 	struct uart_port *port = &stm32port->port;
 	struct device *dev = &pdev->dev;
 	struct dma_slave_config config;
-	struct dma_async_tx_descriptor *desc = NULL;
 	int ret;
 
 	/*
···
 		stm32_usart_of_dma_rx_remove(stm32port, pdev);
 		return ret;
 	}
-
-	/* Prepare a DMA cyclic transaction */
-	desc = dmaengine_prep_dma_cyclic(stm32port->rx_ch,
-					 stm32port->rx_dma_buf,
-					 RX_BUF_L, RX_BUF_P, DMA_DEV_TO_MEM,
-					 DMA_PREP_INTERRUPT);
-	if (!desc) {
-		dev_err(dev, "rx dma prep cyclic failed\n");
-		stm32_usart_of_dma_rx_remove(stm32port, pdev);
-		return -ENODEV;
-	}
-
-	/* No callback as dma buffer is drained on usart interrupt */
-	desc->callback = NULL;
-	desc->callback_param = NULL;
-
-	/* Push current DMA transaction in the pending queue */
-	ret = dma_submit_error(dmaengine_submit(desc));
-	if (ret) {
-		dmaengine_terminate_sync(stm32port->rx_ch);
-		stm32_usart_of_dma_rx_remove(stm32port, pdev);
-		return ret;
-	}
-
-	/* Issue pending DMA requests */
-	dma_async_issue_pending(stm32port->rx_ch);
 
 	return 0;
 }
···
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	int err;
+	u32 cr3;
 
 	pm_runtime_get_sync(&pdev->dev);
 	err = uart_remove_one_port(&stm32_usart_driver, port);
···
 	pm_runtime_set_suspended(&pdev->dev);
 	pm_runtime_put_noidle(&pdev->dev);
 
-	stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+	stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_PEIE);
+	cr3 = readl_relaxed(port->membase + ofs->cr3);
+	cr3 &= ~USART_CR3_EIE;
+	cr3 &= ~USART_CR3_DMAR;
+	cr3 &= ~USART_CR3_DDRE;
+	writel_relaxed(cr3, port->membase + ofs->cr3);
 
 	if (stm32_port->tx_ch) {
 		dmaengine_terminate_async(stm32_port->tx_ch);
···
 	}
 
 	if (stm32_port->rx_ch) {
-		dmaengine_terminate_async(stm32_port->rx_ch);
 		stm32_usart_of_dma_rx_remove(stm32_port, pdev);
 		dma_release_channel(stm32_port->rx_ch);
 	}
···
 	.cons		= STM32_SERIAL_CONSOLE,
 };
 
-static void __maybe_unused stm32_usart_serial_en_wakeup(struct uart_port *port,
-							bool enable)
+static int __maybe_unused stm32_usart_serial_en_wakeup(struct uart_port *port,
+						       bool enable)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+	struct tty_port *tport = &port->state->port;
+	int ret;
+	unsigned int size;
+	unsigned long flags;
 
-	if (!stm32_port->wakeup_src)
-		return;
+	if (!stm32_port->wakeup_src || !tty_port_initialized(tport))
+		return 0;
 
 	/*
 	 * Enable low-power wake-up and wake-up irq if argument is set to
···
 	if (enable) {
 		stm32_usart_set_bits(port, ofs->cr1, USART_CR1_UESM);
 		stm32_usart_set_bits(port, ofs->cr3, USART_CR3_WUFIE);
+
+		/*
+		 * When DMA is used for reception, it must be disabled before
+		 * entering low-power mode and re-enabled when exiting from
+		 * low-power mode.
+		 */
+		if (stm32_port->rx_ch) {
+			spin_lock_irqsave(&port->lock, flags);
+			/* Avoid race with RX IRQ when DMAR is cleared */
+			stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
+			/* Poll data from DMA RX buffer if any */
+			size = stm32_usart_receive_chars(port, true);
+			dmaengine_terminate_async(stm32_port->rx_ch);
+			uart_unlock_and_check_sysrq_irqrestore(port, flags);
+			if (size)
+				tty_flip_buffer_push(tport);
+		}
+
+		/* Poll data from RX FIFO if any */
+		stm32_usart_receive_chars(port, false);
 	} else {
+		if (stm32_port->rx_ch) {
+			ret = stm32_usart_start_rx_dma_cyclic(port);
+			if (ret)
+				return ret;
+		}
+
 		stm32_usart_clr_bits(port, ofs->cr1, USART_CR1_UESM);
 		stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_WUFIE);
 	}
+
+	return 0;
 }
 
 static int __maybe_unused stm32_usart_serial_suspend(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
+	int ret;
 
 	uart_suspend_port(&stm32_usart_driver, port);
 
-	if (device_may_wakeup(dev) || device_wakeup_path(dev))
-		stm32_usart_serial_en_wakeup(port, true);
+	if (device_may_wakeup(dev) || device_wakeup_path(dev)) {
+		ret = stm32_usart_serial_en_wakeup(port, true);
+		if (ret)
+			return ret;
+	}
 
 	/*
 	 * When "no_console_suspend" is enabled, keep the pinctrl default state
···
 static int __maybe_unused stm32_usart_serial_resume(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
+	int ret;
 
 	pinctrl_pm_select_default_state(dev);
 
-	if (device_may_wakeup(dev) || device_wakeup_path(dev))
-		stm32_usart_serial_en_wakeup(port, false);
+	if (device_may_wakeup(dev) || device_wakeup_path(dev)) {
+		ret = stm32_usart_serial_en_wakeup(port, false);
+		if (ret)
+			return ret;
+	}
 
 	return uart_resume_port(&stm32_usart_driver, port);
 }

drivers/tty/serial/stm32-usart.h

···
 /* USART_SR (F4) / USART_ISR (F7) */
 #define USART_SR_PE		BIT(0)
 #define USART_SR_FE		BIT(1)
-#define USART_SR_NF		BIT(2)
+#define USART_SR_NE		BIT(2)		/* F7 (NF for F4) */
 #define USART_SR_ORE		BIT(3)
 #define USART_SR_IDLE		BIT(4)
 #define USART_SR_RXNE		BIT(5)
···
 #define USART_SR_SBKF		BIT(18)		/* F7 */
 #define USART_SR_WUF		BIT(20)		/* H7 */
 #define USART_SR_TEACK		BIT(21)		/* F7 */
-#define USART_SR_ERR_MASK	(USART_SR_ORE | USART_SR_FE | USART_SR_PE)
+#define USART_SR_ERR_MASK	(USART_SR_ORE | USART_SR_NE | USART_SR_FE |\
+				 USART_SR_PE)
 /* Dummy bits */
 #define USART_SR_DUMMY_RX	BIT(16)
 
···
 #define STM32_SERIAL_NAME "ttySTM"
 #define STM32_MAX_PORTS 8
 
-#define RX_BUF_L 200		 /* dma rx buffer length     */
-#define RX_BUF_P RX_BUF_L	 /* dma rx buffer period     */
-#define TX_BUF_L 200		 /* dma tx buffer length     */
+#define RX_BUF_L 4096		 /* dma rx buffer length     */
+#define RX_BUF_P (RX_BUF_L / 2)	 /* dma rx buffer period     */
+#define TX_BUF_L RX_BUF_L	 /* dma tx buffer length     */
 
 struct stm32_port {
 	struct uart_port port;
···
 	u32 cr3_irq;		 /* USART_CR3_RXFTIE */
 	int last_res;
 	bool tx_dma_busy;	 /* dma tx busy               */
+	bool throttled;		 /* port throttled            */
 	bool hw_flow_control;
 	bool swap;		 /* swap RX & TX pins */
 	bool fifoen;
···
 	bool wakeup_src;
 	int rdr_mask;		/* receive data register mask */
 	struct mctrl_gpios *gpios; /* modem control gpios */
+	struct dma_tx_state rx_dma_state;
 };
 
 static struct stm32_port stm32_ports[STM32_MAX_PORTS];

drivers/tty/serial/sunzilog.c

···
 
 #define ZS_PUT_CHAR_MAX_DELAY	2000	/* 10 ms */
 
-static void sunzilog_putchar(struct uart_port *port, int ch)
+static void __maybe_unused sunzilog_putchar(struct uart_port *port, int ch)
 {
 	struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
 	int loops = ZS_PUT_CHAR_MAX_DELAY;

drivers/tty/serial/uartlite.c

···
 
 #include <linux/platform_device.h>
 #include <linux/module.h>
+#include <linux/bitfield.h>
 #include <linux/console.h>
 #include <linux/serial.h>
 #include <linux/serial_core.h>
···
 static struct uart_port *console_port;
 #endif
 
+/**
+ * struct uartlite_data: Driver private data
+ * reg_ops: Functions to read/write registers
+ * clk: Our parent clock, if present
+ * baud: The baud rate configured when this device was synthesized
+ * cflags: The cflags for parity and data bits
+ */
 struct uartlite_data {
 	const struct uartlite_reg_ops *reg_ops;
 	struct clk *clk;
+	unsigned int baud;
+	tcflag_t cflags;
 };
 
 struct uartlite_reg_ops {
···
 }
 
 static struct uart_port ulite_ports[ULITE_NR_UARTS];
+
+static struct uart_driver ulite_uart_driver;
 
 /* ---------------------------------------------------------------------
  * Core UART driver operations
···
 			      struct ktermios *old)
 {
 	unsigned long flags;
-	unsigned int baud;
+	struct uartlite_data *pdata = port->private_data;
+
+	/* Set termios to what the hardware supports */
+	termios->c_cflag &= ~(BRKINT | CSTOPB | PARENB | PARODD | CSIZE);
+	termios->c_cflag |= pdata->cflags & (PARENB | PARODD | CSIZE);
+	tty_termios_encode_baud_rate(termios, pdata->baud, pdata->baud);
 
 	spin_lock_irqsave(&port->lock, flags);
 
···
 			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
 
 	/* update timeout */
-	baud = uart_get_baud_rate(port, termios, old, 0, 460800);
-	uart_update_timeout(port, termios->c_cflag, baud);
+	uart_update_timeout(port, termios->c_cflag, pdata->baud);
 
 	spin_unlock_irqrestore(&port->lock, flags);
 }
···
 
 	return uart_set_options(port, co, baud, parity, bits, flow);
 }
-
-static struct uart_driver ulite_uart_driver;
 
 static struct console ulite_console = {
 	.name	= ULITE_NAME,
···
 	struct uartlite_data *pdata;
 	int irq, ret;
 	int id = pdev->id;
-#ifdef CONFIG_OF
-	const __be32 *prop;
 
-	prop = of_get_property(pdev->dev.of_node, "port-number", NULL);
-	if (prop)
-		id = be32_to_cpup(prop);
-#endif
 	pdata = devm_kzalloc(&pdev->dev, sizeof(struct uartlite_data),
 			     GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
+
+	if (IS_ENABLED(CONFIG_OF)) {
+		const char *prop;
+		struct device_node *np = pdev->dev.of_node;
+		u32 val = 0;
+
+		prop = "port-number";
+		ret = of_property_read_u32(np, prop, &id);
+		if (ret && ret != -EINVAL)
+of_err:
+			return dev_err_probe(&pdev->dev, ret,
+					     "could not read %s\n", prop);
+
+		prop = "current-speed";
+		ret = of_property_read_u32(np, prop, &pdata->baud);
+		if (ret)
+			goto of_err;
+
+		prop = "xlnx,use-parity";
+		ret = of_property_read_u32(np, prop, &val);
+		if (ret && ret != -EINVAL)
+			goto of_err;
+
+		if (val) {
+			prop = "xlnx,odd-parity";
+			ret = of_property_read_u32(np, prop, &val);
+			if (ret)
+				goto of_err;
+
+			if (val)
+				pdata->cflags |= PARODD;
+			pdata->cflags |= PARENB;
+		}
+
+		val = 8;
+		prop = "xlnx,data-bits";
+		ret = of_property_read_u32(np, prop, &val);
+		if (ret && ret != -EINVAL)
+			goto of_err;
+
+		switch (val) {
+		case 5:
+			pdata->cflags |= CS5;
+			break;
+		case 6:
+			pdata->cflags |= CS6;
+			break;
+		case 7:
+			pdata->cflags |= CS7;
+			break;
+		case 8:
+			pdata->cflags |= CS8;
+			break;
+		default:
+			return dev_err_probe(&pdev->dev, -EINVAL,
+					     "bad data bits %d\n", val);
+		}
+	} else {
+		pdata->baud = 9600;
+		pdata->cflags = CS8;
+	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)

drivers/tty/serial/xilinx_uartps.c

···
 	if (uart_circ_empty(&port->state->xmit))
 		return;
 
+	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
+
 	cdns_uart_handle_tx(port);
 
-	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
 	/* Enable the TX Empty interrupt */
 	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IER);
 }

drivers/tty/sysrq.c

···
 			sysrq->shift = KEY_RESERVED;
 		else if (value != 2)
 			sysrq->shift = code;
+		if (sysrq->active)
+			sysrq->shift_use = sysrq->shift;
 		break;
 
 	case KEY_SYSRQ:

drivers/tty/tty_baudrate.c

···
 	termios->c_ospeed = obaud;
 
 #ifdef IBSHIFT
-	if ((termios->c_cflag >> IBSHIFT) & CBAUD)
+	if (((termios->c_cflag >> IBSHIFT) & CBAUD) != B0)
 		ibinput = 1;	/* An input speed was specified */
 #endif
 #ifdef BOTHER

drivers/tty/tty_buffer.c

···
 		if (!count)
 			break;
 		head->read += count;
+
+		if (need_resched())
+			cond_resched();
 	}
 
 	mutex_unlock(&buf->lock);

drivers/tty/tty_ioctl.c

···
 /**
  *	tty_mode_ioctl		-	mode related ioctls
  *	@tty: tty for the ioctl
- *	@file: file pointer for the tty
  *	@cmd: command
  *	@arg: ioctl argument
  *
···
  *	consistent mode setting.
  */
 
-int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
-			unsigned int cmd, unsigned long arg)
+int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 {
 	struct tty_struct *real_tty;
 	void __user *p = (void __user *)arg;
 	int ret = 0;
 	struct ktermios kterm;
-
-	BUG_ON(file == NULL);
 
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
 	    tty->driver->subtype == PTY_TYPE_MASTER)
···
 }
 EXPORT_SYMBOL_GPL(tty_perform_flush);
 
-int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
-		       unsigned int cmd, unsigned long arg)
+int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
+		unsigned long arg)
 {
 	int retval;
 
···
 		return __tty_perform_flush(tty, arg);
 	default:
 		/* Try the mode commands */
-		return tty_mode_ioctl(tty, file, cmd, arg);
+		return tty_mode_ioctl(tty, cmd, arg);
 	}
 }
 EXPORT_SYMBOL(n_tty_ioctl_helper);

include/linux/console.h

···
 	short	flags;
 	short	index;
 	int	cflag;
+	uint	ispeed;
+	uint	ospeed;
 	void	*data;
 	struct	 console *next;
 };

include/linux/rpmsg.h

···
 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 			poll_table *wait);
 
+ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
+
 #else
 
 static inline int rpmsg_register_device(struct rpmsg_device *rpdev)
···
 	WARN_ON(1);
 
 	return 0;
+}
+
+static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
+{
+	/* This shouldn't be possible */
+	WARN_ON(1);
+
+	return -ENXIO;
 }
 
 #endif /* IS_ENABLED(CONFIG_RPMSG) */

include/linux/tty.h

···
 }
 
 #ifdef CONFIG_TTY
-extern void tty_kref_put(struct tty_struct *tty);
-extern struct pid *tty_get_pgrp(struct tty_struct *tty);
-extern void tty_vhangup_self(void);
-extern void disassociate_ctty(int priv);
-extern dev_t tty_devnum(struct tty_struct *tty);
-extern void proc_clear_tty(struct task_struct *p);
-extern struct tty_struct *get_current_tty(void);
+void tty_kref_put(struct tty_struct *tty);
+struct pid *tty_get_pgrp(struct tty_struct *tty);
+void tty_vhangup_self(void);
+void disassociate_ctty(int priv);
+dev_t tty_devnum(struct tty_struct *tty);
+void proc_clear_tty(struct task_struct *p);
+struct tty_struct *get_current_tty(void);
 /* tty_io.c */
-extern int __init tty_init(void);
-extern const char *tty_name(const struct tty_struct *tty);
-extern struct tty_struct *tty_kopen_exclusive(dev_t device);
-extern struct tty_struct *tty_kopen_shared(dev_t device);
-extern void tty_kclose(struct tty_struct *tty);
-extern int tty_dev_name_to_number(const char *name, dev_t *number);
+int __init tty_init(void);
+const char *tty_name(const struct tty_struct *tty);
+struct tty_struct *tty_kopen_exclusive(dev_t device);
+struct tty_struct *tty_kopen_shared(dev_t device);
+void tty_kclose(struct tty_struct *tty);
+int tty_dev_name_to_number(const char *name, dev_t *number);
 #else
 static inline void tty_kref_put(struct tty_struct *tty)
 { }
···
 
 extern struct ktermios tty_std_termios;
 
-extern int vcs_init(void);
+int vcs_init(void);
 
 extern struct class *tty_class;
 
···
 	return tty;
 }
 
-extern const char *tty_driver_name(const struct tty_struct *tty);
-extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
-extern void stop_tty(struct tty_struct *tty);
-extern void start_tty(struct tty_struct *tty);
-extern void tty_write_message(struct tty_struct *tty, char *msg);
-extern int tty_send_xchar(struct tty_struct *tty, char ch);
-extern int tty_put_char(struct tty_struct *tty, unsigned char c);
-extern unsigned int tty_chars_in_buffer(struct tty_struct *tty);
-extern unsigned int tty_write_room(struct tty_struct *tty);
-extern void tty_driver_flush_buffer(struct tty_struct *tty);
-extern void tty_unthrottle(struct tty_struct *tty);
-extern int tty_throttle_safe(struct tty_struct *tty);
-extern int tty_unthrottle_safe(struct tty_struct *tty);
-extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
-extern int tty_get_icount(struct tty_struct *tty,
-			  struct serial_icounter_struct *icount);
-extern int is_current_pgrp_orphaned(void);
-extern void tty_hangup(struct tty_struct *tty);
-extern void tty_vhangup(struct tty_struct *tty);
-extern int tty_hung_up_p(struct file *filp);
-extern void do_SAK(struct tty_struct *tty);
-extern void __do_SAK(struct tty_struct *tty);
-extern void no_tty(void);
-extern speed_t tty_termios_baud_rate(struct ktermios *termios);
-extern void tty_termios_encode_baud_rate(struct ktermios *termios,
-						speed_t ibaud, speed_t obaud);
-extern void tty_encode_baud_rate(struct tty_struct *tty,
-						speed_t ibaud, speed_t obaud);
+const char *tty_driver_name(const struct tty_struct *tty);
+void tty_wait_until_sent(struct tty_struct *tty, long timeout);
+void stop_tty(struct tty_struct *tty);
+void start_tty(struct tty_struct *tty);
+void tty_write_message(struct tty_struct *tty, char *msg);
+int tty_send_xchar(struct tty_struct *tty, char ch);
+int tty_put_char(struct tty_struct *tty, unsigned char c);
+unsigned int tty_chars_in_buffer(struct tty_struct *tty);
+unsigned int tty_write_room(struct tty_struct *tty);
+void tty_driver_flush_buffer(struct tty_struct *tty);
+void tty_unthrottle(struct tty_struct *tty);
+int tty_throttle_safe(struct tty_struct *tty);
+int tty_unthrottle_safe(struct tty_struct *tty);
+int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
+int tty_get_icount(struct tty_struct *tty,
+		struct serial_icounter_struct *icount);
+int is_current_pgrp_orphaned(void);
+void tty_hangup(struct tty_struct *tty);
+void tty_vhangup(struct tty_struct *tty);
+int tty_hung_up_p(struct file *filp);
+void do_SAK(struct tty_struct *tty);
+void __do_SAK(struct tty_struct *tty);
+void no_tty(void);
+speed_t tty_termios_baud_rate(struct ktermios *termios);
+void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud,
+		speed_t obaud);
+void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud,
+		speed_t obaud);
 
 /**
  *	tty_get_baud_rate	-	get tty bit rates
···
 unsigned char tty_get_char_size(unsigned int cflag);
 unsigned char tty_get_frame_size(unsigned int cflag);
 
-extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
-extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
-extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
+void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
+int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
+int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 
-extern void tty_wakeup(struct tty_struct *tty);
+void tty_wakeup(struct tty_struct *tty);
 
-extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
-			unsigned int cmd, unsigned long arg);
-extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
-extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
-extern void tty_release_struct(struct tty_struct *tty, int idx);
-extern void tty_init_termios(struct tty_struct *tty);
-extern void tty_save_termios(struct tty_struct *tty);
-extern int tty_standard_install(struct tty_driver *driver,
+int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
+int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
+struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
+void tty_release_struct(struct tty_struct *tty, int idx);
+void tty_init_termios(struct tty_struct *tty);
+void tty_save_termios(struct tty_struct *tty);
+int tty_standard_install(struct tty_driver *driver,
 		struct tty_struct *tty);
 
 extern struct mutex tty_mutex;
 
 /* n_tty.c */
-extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
+void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
 #ifdef CONFIG_TTY
-extern void __init n_tty_init(void);
+void __init n_tty_init(void);
 #else
 static inline void n_tty_init(void) { }
 #endif
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT
-extern void tty_audit_exit(void);
-extern void tty_audit_fork(struct signal_struct *sig);
-extern int tty_audit_push(void);
+void tty_audit_exit(void);
+void tty_audit_fork(struct signal_struct *sig);
+int tty_audit_push(void);
 #else
 static inline void tty_audit_exit(void)
 {
···
 #endif
 
 /* tty_ioctl.c */
-extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
-		       unsigned int cmd, unsigned long arg);
+int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
+		unsigned long arg);
 
 /* vt.c */
 
-extern int vt_ioctl(struct tty_struct *tty,
-		    unsigned int cmd, unsigned long arg);
+int vt_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg);
 
-extern long vt_compat_ioctl(struct tty_struct *tty,
-		     unsigned int cmd, unsigned long arg);
+long vt_compat_ioctl(struct tty_struct *tty, unsigned int cmd,
+		unsigned long arg);
 
 /* tty_mutex.c */
 /* functions for preparation of BKL removal */
-extern void tty_lock(struct tty_struct *tty);
-extern int  tty_lock_interruptible(struct tty_struct *tty);
-extern void tty_unlock(struct tty_struct *tty);
-extern void tty_lock_slave(struct tty_struct *tty);
-extern void tty_unlock_slave(struct tty_struct *tty);
-extern void tty_set_lock_subclass(struct tty_struct *tty);
+void tty_lock(struct tty_struct *tty);
+int  tty_lock_interruptible(struct tty_struct *tty);
+void tty_unlock(struct tty_struct *tty);
+void tty_lock_slave(struct tty_struct *tty);
+void tty_unlock_slave(struct tty_struct *tty);
+void tty_set_lock_subclass(struct tty_struct *tty);
 
 #endif

include/linux/tty_driver.h

···
 
 extern struct list_head tty_drivers;
 
-extern struct tty_driver *__tty_alloc_driver(unsigned int lines,
-		struct module *owner, unsigned long flags);
-extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
+struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
+		unsigned long flags);
+struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
-extern void tty_driver_kref_put(struct tty_driver *driver);
+void tty_driver_kref_put(struct tty_driver *driver);
 
 /* Use TTY_DRIVER_* flags below */
 #define tty_alloc_driver(lines, flags) \
···
  * 	Used for PTY's, in particular.
  * 
  * TTY_DRIVER_REAL_RAW --- if set, indicates that the driver will
- * 	guarantee never not to set any special character handling
+ * 	guarantee never to set any special character handling
  * 	flags if ((IGNBRK || (!BRKINT && !PARMRK)) && (IGNPAR ||
  * 	!INPCK)).  That is, if there is no reason for the driver to
  * 	send notifications of parity and break characters up to the

include/linux/tty_flip.h

···
 
 struct tty_ldisc;
 
-extern int tty_buffer_set_limit(struct tty_port *port, int limit);
-extern unsigned int tty_buffer_space_avail(struct tty_port *port);
-extern int tty_buffer_request_room(struct tty_port *port, size_t size);
-extern int tty_insert_flip_string_flags(struct tty_port *port,
+int tty_buffer_set_limit(struct tty_port *port, int limit);
+unsigned int tty_buffer_space_avail(struct tty_port *port);
+int tty_buffer_request_room(struct tty_port *port, size_t size);
+int tty_insert_flip_string_flags(struct tty_port *port,
 		const unsigned char *chars, const char *flags, size_t size);
-extern int tty_insert_flip_string_fixed_flag(struct tty_port *port,
+int tty_insert_flip_string_fixed_flag(struct tty_port *port,
 		const unsigned char *chars, char flag, size_t size);
-extern int tty_prepare_flip_string(struct tty_port *port,
-		unsigned char **chars, size_t size);
-extern void tty_flip_buffer_push(struct tty_port *port);
+int tty_prepare_flip_string(struct tty_port *port, unsigned char **chars,
+		size_t size);
+void tty_flip_buffer_push(struct tty_port *port);
 void tty_schedule_flip(struct tty_port *port);
 int __tty_insert_flip_char(struct tty_port *port, unsigned char ch, char flag);
 
···
 int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
 		const char *f, int count);
 
-extern void tty_buffer_lock_exclusive(struct tty_port *port);
-extern void tty_buffer_unlock_exclusive(struct tty_port *port);
+void tty_buffer_lock_exclusive(struct tty_port *port);
+void tty_buffer_unlock_exclusive(struct tty_port *port);
 
 #endif /* _LINUX_TTY_FLIP_H */

include/linux/tty_ldisc.h

···
 #endif
 };
 
-extern void __init_ldsem(struct ld_semaphore *sem, const char *name,
+void __init_ldsem(struct ld_semaphore *sem, const char *name,
 			 struct lock_class_key *key);
 
 #define init_ldsem(sem)						\
···
 } while (0)
 
 
-extern int ldsem_down_read(struct ld_semaphore *sem, long timeout);
-extern int ldsem_down_read_trylock(struct ld_semaphore *sem);
-extern int ldsem_down_write(struct ld_semaphore *sem, long timeout);
-extern int ldsem_down_write_trylock(struct ld_semaphore *sem);
-extern void ldsem_up_read(struct ld_semaphore *sem);
-extern void ldsem_up_write(struct ld_semaphore *sem);
+int ldsem_down_read(struct ld_semaphore *sem, long timeout);
+int ldsem_down_read_trylock(struct ld_semaphore *sem);
+int ldsem_down_write(struct ld_semaphore *sem, long timeout);
+int ldsem_down_write_trylock(struct ld_semaphore *sem);
+void ldsem_up_read(struct ld_semaphore *sem);
+void ldsem_up_write(struct ld_semaphore *sem);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-extern int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass,
-				  long timeout);
-extern int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
-				   long timeout);
+int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass,
+		long timeout);
+int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass,
+		long timeout);
 #else
 # define ldsem_down_read_nested(sem, subclass, timeout)		\
 		ldsem_down_read(sem, timeout)
···
 struct tty_ldisc_ops {
 	char	*name;
 	int	num;
-	int	flags;
 
 	/*
 	 * The following routines are called from above.
···
 	void	(*set_termios)(struct tty_struct *tty, struct ktermios *old);
 	__poll_t (*poll)(struct tty_struct *, struct file *,
 			     struct poll_table_struct *);
-	int	(*hangup)(struct tty_struct *tty);
+	void	(*hangup)(struct tty_struct *tty);
 
 	/*
 	 * The following routines are called from below.
···
 	struct tty_ldisc_ops *ops;
 	struct tty_struct *tty;
 };
-
-#define LDISC_FLAG_DEFINED	0x00000001
 
 #define MODULE_ALIAS_LDISC(ldisc) \
 	MODULE_ALIAS("tty-ldisc-" __stringify(ldisc))

net/nfc/nci/uart.c

···
 			return -EBUSY;
 		break;
 	default:
-		err = n_tty_ioctl_helper(tty, file, cmd, arg);
+		err = n_tty_ioctl_helper(tty, cmd, arg);
 		break;
 	}
 

sound/soc/codecs/cx20442.c

···
 }
 
 /* Line discipline .hangup() */
-static int v253_hangup(struct tty_struct *tty)
+static void v253_hangup(struct tty_struct *tty)
 {
 	v253_close(tty);
-	return 0;
 }
 
 /* Line discipline .receive_buf() */

sound/soc/ti/ams-delta.c

···
 }
 
 /* Line discipline .hangup() */
-static int cx81801_hangup(struct tty_struct *tty)
+static void cx81801_hangup(struct tty_struct *tty)
 {
 	cx81801_close(tty);
-	return 0;
 }
 
 /* Line discipline .receive_buf() */