This reverts commit 5c7e105cd156fc9adf5294a83623d7a40c15f9b9.

As identified by KASAN, the simplification done by the cleanup patch
was not legal.

>From tracing through the code, it can be seen that we're transmitting
from a 4096-byte circular buffer. We copy anywhere from 1-4 bytes from
it each time. The simplification runs into trouble when we get near
the end of the circular buffer. For instance, we might start out with
xmit->tail = 4094 and we want to transfer 4 bytes. With the code
before simplification this was no problem. We'd read buf[4094],
buf[4095], buf[0], and buf[1]. With the new code we'll do a
memcpy(&buf[4094], 4) which reads 2 bytes past the end of the buffer
and then skips transmitting what's at buf[0] and buf[1].

KASAN isn't 100% consistent at reporting this for me, but to be extra
confident in the analysis, I added traces of the tail and tx_bytes and
then wrote a test program:

while true; do
echo -n "abcdefghijklmnopqrstuvwxyz0" > /dev/ttyMSM0
sleep .1
done

I watched the traces over SSH and saw:
qcom_geni_serial_send_chunk_fifo: 4093 4
qcom_geni_serial_send_chunk_fifo: 1 3

Which indicated that one byte should be missing. Sure enough the
output that should have been:

abcdefghijklmnopqrstuvwxyz0

In one case was actually missing a byte:

abcdefghijklmnopqrstuvwyz0

Running "ls -al" on large directories also made the missing bytes
obvious since columns didn't line up.

While the original code may not be the most elegant, we only talking
about copying up to 4 bytes here. Let's just go back to the code that
worked.

Fixes: 5c7e105cd156 ("tty: serial: simplify qcom_geni_serial_send_chunk_fifo()")
Cc: stable <stable@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240304174952.1.I920a314049b345efd1f69d708e7f74d2213d0b49@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If the remote uart device is not connected or not enabled after booting
up, the CTS line is high by default. At this time, if we enable the flow
control when opening the device(for example, using “stty -F /dev/ttyLP4
crtscts” command), there will be a pending idle preamble(first writing 0
and then writing 1 to UARTCTRL_TE will queue an idle preamble) that
cannot be sent out, resulting in the uart port fail to close(waiting for
TX empty), so the user space stty will have to wait for a long time or
forever.

This is an LPUART IP bug(idle preamble has higher priority than CTS),
here add a workaround patch to enable TX CTS after enabling UARTCTRL_TE,
so that the idle preamble does not get stuck due to CTS is deasserted.

Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Cc: stable <stable@kernel.org>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://lore.kernel.org/r/20240305015706.1050769-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This is the same issue that was fixed for the VGA text buffer in commit
39cdb68c64d8 ("vt: fix memory overlapping when deleting chars in the
buffer"). The cure is also the same i.e. replace memcpy() with memmove()
due to the overlaping buffers.

Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition")
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/sn184on2-3p0q-0qrq-0218-895349s4753o@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We accidently met the issue that the bash prompt is not shown after the
previous command done and until the next input if there's only one CPU
(In our issue other CPUs are isolated by isolcpus=). Further analysis
shows it's because the port entering runtime suspend even if there's
still pending chars in the buffer and the pending chars will only be
processed in next device resuming. We are using amba-pl011 and the
problematic flow is like below:

Bash                                         kworker
tty_write()
  file_tty_write()
    n_tty_write()
      uart_write()
        __uart_start()
          pm_runtime_get() // wakeup waker
            queue_work()
                                    pm_runtime_work()
                                               rpm_resume()
                                                status = RPM_RESUMING
                                                serial_port_runtime_resume()
                                                  port->ops->start_tx()
                                                    pl011_tx_chars()
                                                      uart_write_wakeup()
        […]
        __uart_start()
          pm_runtime_get() < 0 // because runtime status = RPM_RESUMING
                               // later data are not commit to the port driver
                                                status = RPM_ACTIVE
                                                rpm_idle() -> rpm_suspend()

This patch tries to fix this by checking the port busy before entering
runtime suspending. A runtime_suspend callback is added for the port
driver. When entering runtime suspend the callback is invoked, if there's
still pending chars in the buffer then flush the buffer.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable <stable@kernel.org>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20240226152351.40924-1-yangyicong@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When userspace opens the console, we call set_termios() passing a
termios with the console's configured baud rate. Currently this causes
dw8250_set_termios() to disable and then re-enable the UART clock at
the same frequency as it was originally. This can cause corruption
of any concurrent console output. Fix it by skipping the reclocking
if we are already at the correct rate.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Fixes: 4e26b134bd17 ("serial: 8250_dw: clock rate handling for all ACPI platforms")
Cc: stable@vger.kernel.org
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240222192635.1050502-1-pcc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When about to transmit the function imx_uart_start_tx is called and in
some RS485 configurations this function will call imx_uart_stop_rx. The
problem is that imx_uart_stop_rx will enable loopback in order to
release the RS485 bus, but when loopback is enabled transmitted data
will just be looped to RX.

This patch fixes the above problem by not enabling loopback when about
to transmit.

This driver now works well when used for RS485 half duplex master
configurations.

Fixes: 79d0224f6bf2 ("tty: serial: imx: Handle RS485 DE signal active high")
Cc: stable <stable@kernel.org>
Signed-off-by: Rickard x Andersson <rickaran@axis.com>
Tested-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Link: https://lore.kernel.org/r/20240221115304.509811-1-rickaran@axis.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull bcachefs fixes from Kent Overstreet:
"Some more mostly boring fixes, but some not

User reported ones:

- the BTREE_ITER_FILTER_SNAPSHOTS one fixes a really nasty
performance bug; user reported an untar initially taking two
seconds and then ~2 minutes

- kill a __GFP_NOFAIL in the buffered read path; this was a leftover
from the trickier fix to kill __GFP_NOFAIL in readahead, where we
can't return errors (and have to silently truncate the read
ourselves).

bcachefs can't use GFP_NOFAIL for folio state unlike iomap based
filesystems because our folio state is just barely too big, 2MB
hugepages cause us to exceed the 2 page threshhold for GFP_NOFAIL.

additionally, the flags argument was just buggy, we weren't
supplying GFP_KERNEL previously (!)"

* tag 'bcachefs-2024-02-25' of https://evilpiepirate.org/git/bcachefs:
bcachefs: fix bch2_save_backtrace()
bcachefs: Fix check_snapshot() memcpy
bcachefs: Fix bch2_journal_flush_device_pins()
bcachefs: fix iov_iter count underflow on sub-block dio read
bcachefs: Fix BTREE_ITER_FILTER_SNAPSHOTS on inodes btree
bcachefs: Kill __GFP_NOFAIL in buffered read path
bcachefs: fix backpointer_to_text() when dev does not exist

Pull two documentation build fixes from Jonathan Corbet:

- The XFS online fsck documentation uses incredibly deeply nested
subsection and list nesting; that broke the PDF docs build. Tweak a
parameter to tell LaTeX to allow the deeper nesting.

- Fix a 6.8 PDF-build regression

* tag 'docs-6.8-fixes3' of git://git.lwn.net/linux:
docs: translations: use attribute to store current language
docs: Instruct LaTeX to cope with deeper nesting

Missed a call in the previous fix.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Pull USB fixes from Greg KH:
"Here are some small USB fixes for 6.8-rc6 to resolve some reported
problems. These include:

- regression fixes with typec tpcm code as reported by many

- cdnsp and cdns3 driver fixes

- usb role setting code bugfixes

- build fix for uhci driver

- ncm gadget driver bugfix

- MAINTAINERS entry update

All of these have been in linux-next all week with no reported issues
and there is at least one fix in here that is in Thorsten's regression
list that is being tracked"

* tag 'usb-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: typec: tpcm: Fix issues with power being removed during reset
MAINTAINERS: Drop myself as maintainer of TYPEC port controller drivers
usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs
Revert "usb: typec: tcpm: reset counter when enter into unattached state after try role"
usb: gadget: omap_udc: fix USB gadget regression on Palm TE
usb: dwc3: gadget: Don't disconnect if not started
usb: cdns3: fix memory double free when handle zero packet
usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()
usb: roles: don't get/set_role() when usb_role_switch is unregistered
usb: roles: fix NULL pointer issue when put module's reference
usb: cdnsp: fixed issue with incorrect detecting CDNSP family controllers
usb: cdnsp: blocked some cdns3 specific code
usb: uhci-grlib: Explicitly include linux/platform_device.h

Akira Yokosawa reported [1] that the "translations" extension we added in
commit 7418ec5b151f ("docs: translations: add translations links when they
exist") broke the build on Sphinx versions v6.1.3 through 7.1.2 (possibly
others) with the following error:

Exception occurred:
File "/usr/lib/python3.12/site-packages/sphinx/util/nodes.py", line 624, in _copy_except__document
newnode = self.__class__(rawsource=self.rawsource, **self.attributes)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: LanguagesNode.__init__() missing 1 required positional argument: 'current_language'
The full traceback has been saved in /tmp/sphinx-err-7xmwytuu.log, if you want to report the issue to the developers.

Solve this problem by making 'current_language' a true element attribute
of the LanguagesNode element, which is probably the more correct way to do
it anyway.

Tested on Sphinx 2.x, 3.x, 6.x, and 7.x.

[1]: https://lore.kernel.org/all/54a56c2e-a27c-45a0-b712-02a7bc7d2673@gmail.com/

Fixes: 7418ec5b151f ("docs: translations: add translations links when they exist")
Reported-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Closes: https://lore.kernel.org/all/54a56c2e-a27c-45a0-b712-02a7bc7d2673@gmail.com/
Tested-by: Akira Yokosawa <akiyks@gmail.com> # Sphinx 4.3.2, 5.3.0 and 6.2.1
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240215064109.1193556-1-vegard.nossum@oracle.com

check_snapshot() copies the bch_snapshot to a temporary to easily handle
older versions that don't have all the fields of the current version,
but it lacked a min() to correctly handle keys newer and larger than the
current version.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Pull tty/serial driver fixes from Greg KH:
"Here are three small serial/tty driver fixes for 6.8-rc6 that resolve
the following reported errors:

- riscv hvc console driver fix that was reported by many

- amba-pl011 serial driver fix for RS485 mode

- stm32 serial driver fix for RS485 mode

All of these have been in linux-next all week with no reported
problems"

* tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: amba-pl011: Fix DMA transmission in RS485 mode
serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabled
tty: hvc: Don't enable the RISC-V SBI console by default

Since the merge of b717dfbf73e8 ("Revert "usb: typec: tcpm: fix
cc role at port reset"") into mainline the LibreTech Renegade
Elite/Firefly has died during boot, the main symptom observed in testing
is a sudden stop in console output. Gábor Stefanik identified in review
that the patch would cause power to be removed from devices without
batteries (like this board), observing that while the patch is correct
according to the spec this appears to be an oversight in the spec.

Given that the change makes previously working systems unusable let's
revert it, there was some discussion of identifying systems that have
alternative power and implementing the standards conforming behaviour in
only that case.

Fixes: b717dfbf73e8 ("Revert "usb: typec: tcpm: fix cc role at port reset"")
Cc: stable <stable@kernel.org>
Cc: Badhri Jagan Sridharan <badhri@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240212-usb-fix-renegade-v1-1-22c43c88d635@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>