tty: drop put_tty_driver

put_tty_driver() is an alias for tty_driver_kref_put(). There is no need
for two exported identical functions, therefore switch all users of
old put_tty_driver() to new tty_driver_kref_put() and remove the former
for good.

Cc: Richard Henderson <[e-mail]>
Cc: Ivan Kokshaysky <[e-mail]>
Cc: Matt Turner <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
Cc: Jeff Dike <[e-mail]>
Cc: Richard Weinberger <[e-mail]>
Cc: Anton Ivanov <[e-mail]>
Cc: Chris Zankel <[e-mail]>
Cc: Max Filippov <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Samuel Iglesias Gonsalvez <[e-mail]>
Cc: Jens Taprogge <[e-mail]>
Cc: Karsten Keil <[e-mail]>
Cc: Scott Branden <[e-mail]>
Cc: Ulf Hansson <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Jakub Kicinski <[e-mail]>
Cc: Heiko Carstens <[e-mail]>
Cc: Vasily Gorbik <[e-mail]>
Cc: Christian Borntraeger <[e-mail]>
Cc: David Lin <[e-mail]>
Cc: Johan Hovold <[e-mail]>
Cc: Alex Elder <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Cc: Laurentiu Tudor <[e-mail]>
Cc: Jiri Kosina <[e-mail]>
Cc: David Sterba <[e-mail]>
Cc: Shawn Guo <[e-mail]>
Cc: Sascha Hauer <[e-mail]>
Cc: Pengutronix Kernel Team <[e-mail]>
Cc: Fabio Estevam <[e-mail]>
Cc: NXP Linux Team <[e-mail]>
Cc: Oliver Neukum <[e-mail]>
Cc: Felipe Balbi <[e-mail]>
Cc: Mathias Nyman <[e-mail]>
Cc: Marcel Holtmann <[e-mail]>
Cc: Johan Hedberg <[e-mail]>
Cc: Luiz Augusto von Dentz <[e-mail]>
Acked-by: Alex Elder <[e-mail]>
Acked-by: Christian Borntraeger <[e-mail]>
Acked-by: Max Filippov <[e-mail]>
Acked-by: David Sterba <[e-mail]>
Acked-by: Samuel Iglesias Gonsálvez <[e-mail]>
Signed-off-by: Jiri Slaby <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

arch/alpha/kernel/srmcons.c

···
 		tty_port_link_device(&srmcons_singleton.port, driver, 0);
 		err = tty_register_driver(driver);
 		if (err) {
-			put_tty_driver(driver);
+			tty_driver_kref_put(driver);
 			tty_port_destroy(&srmcons_singleton.port);
 			return err;
 		}

arch/m68k/emu/nfcon.c

···
 	res = tty_register_driver(driver);
 	if (res) {
 		pr_err("failed to register nfcon tty driver\n");
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		tty_port_destroy(&nfcon_tty_port);
 		return res;
 	}
···
 {
 	unregister_console(&nf_console);
 	tty_unregister_driver(nfcon_tty_driver);
-	put_tty_driver(nfcon_tty_driver);
+	tty_driver_kref_put(nfcon_tty_driver);
 	tty_port_destroy(&nfcon_tty_port);
 }
 

arch/um/drivers/line.c

···
 	if (err) {
 		printk(KERN_ERR "register_lines : can't register %s driver\n",
 		       line_driver->name);
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		for (i = 0; i < nlines; i++)
 			tty_port_destroy(&lines[i].port);
 		return err;

arch/xtensa/platforms/iss/console.c

···
 static __exit void rs_exit(void)
 {
 	tty_unregister_driver(serial_driver);
-	put_tty_driver(serial_driver);
+	tty_driver_kref_put(serial_driver);
 	tty_port_destroy(&serial_port);
 }
 

drivers/char/pcmcia/synclink_cs.c

···
 err_unreg_tty:
 	tty_unregister_driver(serial_driver);
 err_put_tty:
-	put_tty_driver(serial_driver);
+	tty_driver_kref_put(serial_driver);
 err:
 	return rc;
 }
···
 {
 	pcmcia_unregister_driver(&mgslpc_driver);
 	tty_unregister_driver(serial_driver);
-	put_tty_driver(serial_driver);
+	tty_driver_kref_put(serial_driver);
 }
 
 module_init(synclink_cs_init);

drivers/char/ttyprintk.c

···
 	return 0;
 
 error:
-	put_tty_driver(ttyprintk_driver);
+	tty_driver_kref_put(ttyprintk_driver);
 	tty_port_destroy(&tpk_port.port);
 	return ret;
 }
···
 static void __exit ttyprintk_exit(void)
 {
 	tty_unregister_driver(ttyprintk_driver);
-	put_tty_driver(ttyprintk_driver);
+	tty_driver_kref_put(ttyprintk_driver);
 	tty_port_destroy(&tpk_port.port);
 }
 

drivers/ipack/devices/ipoctal.c

···
 	res = tty_register_driver(tty);
 	if (res) {
 		dev_err(&ipoctal->dev->dev, "Can't register tty driver.\n");
-		put_tty_driver(tty);
+		tty_driver_kref_put(tty);
 		return res;
 	}
 
···
 	}
 
 	tty_unregister_driver(ipoctal->tty_drv);
-	put_tty_driver(ipoctal->tty_drv);
+	tty_driver_kref_put(ipoctal->tty_drv);
 	kfree(ipoctal);
 }
 

drivers/isdn/capi/capi.c

···
 
 	err = tty_register_driver(drv);
 	if (err) {
-		put_tty_driver(drv);
+		tty_driver_kref_put(drv);
 		kfree(capiminors);
 		printk(KERN_ERR "Couldn't register capi_nc driver\n");
 		return err;
···
 static void __exit capinc_tty_exit(void)
 {
 	tty_unregister_driver(capinc_tty_driver);
-	put_tty_driver(capinc_tty_driver);
+	tty_driver_kref_put(capinc_tty_driver);
 	kfree(capiminors);
 }
 

drivers/misc/bcm-vk/bcm_vk_tty.c

···
 	tty_drv->name = kstrdup(name, GFP_KERNEL);
 	if (!tty_drv->name) {
 		err = -ENOMEM;
-		goto err_put_tty_driver;
+		goto err_tty_driver_kref_put;
 	}
 	tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
 	tty_drv->subtype = SERIAL_TYPE_NORMAL;
···
 	kfree(tty_drv->name);
 	tty_drv->name = NULL;
 
-err_put_tty_driver:
-	put_tty_driver(tty_drv);
+err_tty_driver_kref_put:
+	tty_driver_kref_put(tty_drv);
 
 	return err;
 }
···
 	kfree(vk->tty_drv->name);
 	vk->tty_drv->name = NULL;
 
-	put_tty_driver(vk->tty_drv);
+	tty_driver_kref_put(vk->tty_drv);
 }
 
 void bcm_vk_tty_terminate_tty_user(struct bcm_vk *vk)

drivers/mmc/core/sdio_uart.c

···
 err2:
 	tty_unregister_driver(tty_drv);
 err1:
-	put_tty_driver(tty_drv);
+	tty_driver_kref_put(tty_drv);
 	return ret;
 }
 
···
 {
 	sdio_unregister_driver(&sdio_uart_driver);
 	tty_unregister_driver(sdio_uart_tty_driver);
-	put_tty_driver(sdio_uart_tty_driver);
+	tty_driver_kref_put(sdio_uart_tty_driver);
 }
 
 module_init(sdio_uart_init);

drivers/net/usb/hso.c

···
 err_unreg_tty:
 	tty_unregister_driver(tty_drv);
 err_free_tty:
-	put_tty_driver(tty_drv);
+	tty_driver_kref_put(tty_drv);
 	return result;
 }
 
···
 	tty_unregister_driver(tty_drv);
 	/* deregister the usb driver */
 	usb_deregister(&hso_driver);
-	put_tty_driver(tty_drv);
+	tty_driver_kref_put(tty_drv);
 }
 
 /* Module definitions */

drivers/s390/char/con3215.c

···
 
 	ret = ccw_driver_register(&raw3215_ccw_driver);
 	if (ret) {
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		return ret;
 	}
 	/*
···
 	tty_set_operations(driver, &tty3215_ops);
 	ret = tty_register_driver(driver);
 	if (ret) {
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		return ret;
 	}
 	tty3215_driver = driver;

drivers/s390/char/sclp_tty.c

···
 
 	rc = sclp_rw_init();
 	if (rc) {
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		return rc;
 	}
 	/* Allocate pages for output buffering */
 	for (i = 0; i < MAX_KMEM_PAGES; i++) {
 		page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 		if (page == NULL) {
-			put_tty_driver(driver);
+			tty_driver_kref_put(driver);
 			return -ENOMEM;
 		}
 		list_add_tail((struct list_head *) page, &sclp_tty_pages);
···
 
 	rc = sclp_register(&sclp_input_event);
 	if (rc) {
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		return rc;
 	}
 
···
 	tty_port_link_device(&sclp_port, driver, 0);
 	rc = tty_register_driver(driver);
 	if (rc) {
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		tty_port_destroy(&sclp_port);
 		return rc;
 	}

drivers/s390/char/sclp_vt220.c

···
 out_init:
 	__sclp_vt220_cleanup();
 out_driver:
-	put_tty_driver(driver);
+	tty_driver_kref_put(driver);
 	return rc;
 }
 __initcall(sclp_vt220_tty_init);

drivers/s390/char/tty3270.c

···
 	tty_set_operations(driver, &tty3270_ops);
 	ret = tty_register_driver(driver);
 	if (ret) {
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		return ret;
 	}
 	tty3270_driver = driver;
···
 	driver = tty3270_driver;
 	tty3270_driver = NULL;
 	tty_unregister_driver(driver);
-	put_tty_driver(driver);
+	tty_driver_kref_put(driver);
 	tty3270_del_views();
 }
 

drivers/staging/fwserial/fwserial.c

···
 		tty_unregister_driver(fwloop_driver);
 put_loop:
 	if (create_loop_dev)
-		put_tty_driver(fwloop_driver);
+		tty_driver_kref_put(fwloop_driver);
 unregister_driver:
 	tty_unregister_driver(fwtty_driver);
 put_tty:
-	put_tty_driver(fwtty_driver);
+	tty_driver_kref_put(fwtty_driver);
 remove_debugfs:
 	debugfs_remove_recursive(fwserial_debugfs);
 
···
 	kmem_cache_destroy(fwtty_txn_cache);
 	if (create_loop_dev) {
 		tty_unregister_driver(fwloop_driver);
-		put_tty_driver(fwloop_driver);
+		tty_driver_kref_put(fwloop_driver);
 	}
 	tty_unregister_driver(fwtty_driver);
-	put_tty_driver(fwtty_driver);
+	tty_driver_kref_put(fwtty_driver);
 	debugfs_remove_recursive(fwserial_debugfs);
 }
 

drivers/staging/gdm724x/gdm_tty.c

···
 
 		ret = tty_register_driver(tty_driver);
 		if (ret) {
-			put_tty_driver(tty_driver);
+			tty_driver_kref_put(tty_driver);
 			return ret;
 		}
 
···
 		tty_driver = gdm_driver[i];
 		if (tty_driver) {
 			tty_unregister_driver(tty_driver);
-			put_tty_driver(tty_driver);
+			tty_driver_kref_put(tty_driver);
 		}
 	}
 }

drivers/staging/greybus/uart.c

···
 	return 0;
 
 fail_put_gb_tty:
-	put_tty_driver(gb_tty_driver);
+	tty_driver_kref_put(gb_tty_driver);
 fail_unregister_dev:
 	return retval;
 }
···
 static void gb_tty_exit(void)
 {
 	tty_unregister_driver(gb_tty_driver);
-	put_tty_driver(gb_tty_driver);
+	tty_driver_kref_put(gb_tty_driver);
 	idr_destroy(&tty_minors);
 }
 

drivers/tty/amiserial.c

···
 
 	error = tty_register_driver(driver);
 	if (error)
-		goto fail_put_tty_driver;
+		goto fail_tty_driver_kref_put;
 
 	printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
 
···
 	free_irq(IRQ_AMIGA_TBE, state);
 fail_unregister:
 	tty_unregister_driver(driver);
-fail_put_tty_driver:
+fail_tty_driver_kref_put:
 	tty_port_destroy(&state->tport);
-	put_tty_driver(driver);
+	tty_driver_kref_put(driver);
 	return error;
 }
 
···
 	struct serial_state *state = platform_get_drvdata(pdev);
 
 	tty_unregister_driver(serial_driver);
-	put_tty_driver(serial_driver);
+	tty_driver_kref_put(serial_driver);
 	tty_port_destroy(&state->tport);
 
 	free_irq(IRQ_AMIGA_TBE, state);

drivers/tty/ehv_bytechan.c

···
 	ret = tty_register_driver(driver);
 	if (ret) {
 		pr_err("ehv-bc: could not register tty driver (ret=%i)\n", ret);
-		goto err_put_tty_driver;
+		goto err_tty_driver_kref_put;
 	}
 
 	ehv_bc_driver = driver;
···
 err_deregister_tty_driver:
 	ehv_bc_driver = NULL;
 	tty_unregister_driver(driver);
-err_put_tty_driver:
-	put_tty_driver(driver);
+err_tty_driver_kref_put:
+	tty_driver_kref_put(driver);
 err_free_bcs:
 	kfree(bcs);
 

drivers/tty/goldfish.c

···
 	return 0;
 
 err_tty_register_driver_failed:
-	put_tty_driver(tty);
+	tty_driver_kref_put(tty);
 err_tty_alloc_driver_failed:
 	kfree(goldfish_ttys);
 	goldfish_ttys = NULL;
···
 static void goldfish_tty_delete_driver(void)
 {
 	tty_unregister_driver(goldfish_tty_driver);
-	put_tty_driver(goldfish_tty_driver);
+	tty_driver_kref_put(goldfish_tty_driver);
 	goldfish_tty_driver = NULL;
 	kfree(goldfish_ttys);
 	goldfish_ttys = NULL;

drivers/tty/hvc/hvc_console.c

···
 	kthread_stop(hvc_task);
 	hvc_task = NULL;
 put_tty:
-	put_tty_driver(drv);
+	tty_driver_kref_put(drv);
 out:
 	return err;
 }

drivers/tty/hvc/hvcs.c

···
 register_fail:
 	hvcs_free_index_list();
 index_fail:
-	put_tty_driver(hvcs_tty_driver);
+	tty_driver_kref_put(hvcs_tty_driver);
 	hvcs_tty_driver = NULL;
 	mutex_unlock(&hvcs_init_mutex);
 	return rc;
···
 
 	hvcs_free_index_list();
 
-	put_tty_driver(hvcs_tty_driver);
+	tty_driver_kref_put(hvcs_tty_driver);
 
 	printk(KERN_INFO "HVCS: driver module removed.\n");
 }

drivers/tty/ipwireless/tty.c

···
 	if (result) {
 		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
 		       ": failed to register tty driver\n");
-		put_tty_driver(ipw_tty_driver);
+		tty_driver_kref_put(ipw_tty_driver);
 		return result;
 	}
 
···
 void ipwireless_tty_release(void)
 {
 	tty_unregister_driver(ipw_tty_driver);
-	put_tty_driver(ipw_tty_driver);
+	tty_driver_kref_put(ipw_tty_driver);
 }
 
 int ipwireless_tty_is_modem(struct ipw_tty *tty)

drivers/tty/mips_ejtag_fdc.c

···
 		dport = &priv->ports[nport];
 		tty_port_destroy(&dport->port);
 	}
-	put_tty_driver(priv->driver);
+	tty_driver_kref_put(priv->driver);
 	return ret;
 }
 

drivers/tty/moxa.c

···
 
 	if (tty_register_driver(moxaDriver)) {
 		printk(KERN_ERR "can't register MOXA Smartio tty driver!\n");
-		put_tty_driver(moxaDriver);
+		tty_driver_kref_put(moxaDriver);
 		return -1;
 	}
 
···
 	del_timer_sync(&moxaTimer);
 
 	tty_unregister_driver(moxaDriver);
-	put_tty_driver(moxaDriver);
+	tty_driver_kref_put(moxaDriver);
 }
 
 module_init(moxa_init);

drivers/tty/mxser.c

···
 err_unr:
 	tty_unregister_driver(mxvar_sdriver);
 err_put:
-	put_tty_driver(mxvar_sdriver);
+	tty_driver_kref_put(mxvar_sdriver);
 	return retval;
 }
 
···
 {
 	pci_unregister_driver(&mxser_driver);
 	tty_unregister_driver(mxvar_sdriver);
-	put_tty_driver(mxvar_sdriver);
+	tty_driver_kref_put(mxvar_sdriver);
 }
 
 module_init(mxser_module_init);

drivers/tty/n_gsm.c

···
 			gsm_tty_driver->major, gsm_tty_driver->minor_start);
 	return 0;
 err_put_driver:
-	put_tty_driver(gsm_tty_driver);
+	tty_driver_kref_put(gsm_tty_driver);
 err_unreg_ldisc:
 	tty_unregister_ldisc(&tty_ldisc_packet);
 	return status;
···
 {
 	tty_unregister_ldisc(&tty_ldisc_packet);
 	tty_unregister_driver(gsm_tty_driver);
-	put_tty_driver(gsm_tty_driver);
+	tty_driver_kref_put(gsm_tty_driver);
 }
 
 module_init(gsm_init);

drivers/tty/nozomi.c

···
 unr_tty:
 	tty_unregister_driver(ntty_driver);
 free_tty:
-	put_tty_driver(ntty_driver);
+	tty_driver_kref_put(ntty_driver);
 	return ret;
 }
 
···
 {
 	pci_unregister_driver(&nozomi_driver);
 	tty_unregister_driver(ntty_driver);
-	put_tty_driver(ntty_driver);
+	tty_driver_kref_put(ntty_driver);
 }
 
 module_init(nozomi_init);

drivers/tty/serial/kgdb_nmi.c

···
 
 	return 0;
 err_drv_reg:
-	put_tty_driver(kgdb_nmi_tty_driver);
+	tty_driver_kref_put(kgdb_nmi_tty_driver);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(kgdb_register_nmi_console);
···
 		return ret;
 
 	tty_unregister_driver(kgdb_nmi_tty_driver);
-	put_tty_driver(kgdb_nmi_tty_driver);
+	tty_driver_kref_put(kgdb_nmi_tty_driver);
 
 	return 0;
 }

drivers/tty/serial/serial_core.c

···
 
 	for (i = 0; i < drv->nr; i++)
 		tty_port_destroy(&drv->state[i].port);
-	put_tty_driver(normal);
+	tty_driver_kref_put(normal);
 out_kfree:
 	kfree(drv->state);
 out:
···
 	unsigned int i;
 
 	tty_unregister_driver(p);
-	put_tty_driver(p);
+	tty_driver_kref_put(p);
 	for (i = 0; i < drv->nr; i++)
 		tty_port_destroy(&drv->state[i].port);
 	kfree(drv->state);

drivers/tty/synclink_gt.c

···
 		for (info=slgt_device_list ; info != NULL ; info=info->next_device)
 			tty_unregister_device(serial_driver, info->line);
 		tty_unregister_driver(serial_driver);
-		put_tty_driver(serial_driver);
+		tty_driver_kref_put(serial_driver);
 	}
 
 	/* reset devices */
···
 	tty_set_operations(serial_driver, &ops);
 	if ((rc = tty_register_driver(serial_driver)) < 0) {
 		DBGERR(("%s can't register serial driver\n", driver_name));
-		put_tty_driver(serial_driver);
+		tty_driver_kref_put(serial_driver);
 		serial_driver = NULL;
 		goto error;
 	}

drivers/tty/tty_io.c

···
 }
 EXPORT_SYMBOL(tty_driver_kref_put);
 
-void put_tty_driver(struct tty_driver *d)
-{
-	tty_driver_kref_put(d);
-}
-EXPORT_SYMBOL(put_tty_driver);
-
 /*
  * Called by a tty driver to register itself.
  */

drivers/tty/ttynull.c

···
 
 	ret = tty_register_driver(driver);
 	if (ret < 0) {
-		put_tty_driver(driver);
+		tty_driver_kref_put(driver);
 		tty_port_destroy(&ttynull_port);
 		return ret;
 	}
···
 {
 	unregister_console(&ttynull_console);
 	tty_unregister_driver(ttynull_driver);
-	put_tty_driver(ttynull_driver);
+	tty_driver_kref_put(ttynull_driver);
 	tty_port_destroy(&ttynull_port);
 }
 

drivers/tty/vcc.c

···
 	rv = tty_register_driver(vcc_tty_driver);
 	if (rv) {
 		pr_err("VCC: TTY driver registration failed\n");
-		put_tty_driver(vcc_tty_driver);
+		tty_driver_kref_put(vcc_tty_driver);
 		vcc_tty_driver = NULL;
 		return rv;
 	}
···
 static void vcc_tty_exit(void)
 {
 	tty_unregister_driver(vcc_tty_driver);
-	put_tty_driver(vcc_tty_driver);
+	tty_driver_kref_put(vcc_tty_driver);
 	vccdbg("VCC: TTY driver unregistered\n");
 
 	vcc_tty_driver = NULL;

drivers/usb/class/cdc-acm.c

···
 
 	retval = tty_register_driver(acm_tty_driver);
 	if (retval) {
-		put_tty_driver(acm_tty_driver);
+		tty_driver_kref_put(acm_tty_driver);
 		return retval;
 	}
 
 	retval = usb_register(&acm_driver);
 	if (retval) {
 		tty_unregister_driver(acm_tty_driver);
-		put_tty_driver(acm_tty_driver);
+		tty_driver_kref_put(acm_tty_driver);
 		return retval;
 	}
 
···
 {
 	usb_deregister(&acm_driver);
 	tty_unregister_driver(acm_tty_driver);
-	put_tty_driver(acm_tty_driver);
+	tty_driver_kref_put(acm_tty_driver);
 	idr_destroy(&acm_minors);
 }
 

drivers/usb/gadget/function/u_serial.c

···
 
 	return status;
 fail:
-	put_tty_driver(driver);
+	tty_driver_kref_put(driver);
 	return status;
 }
 module_init(userial_init);
···
 static void userial_cleanup(void)
 {
 	tty_unregister_driver(gs_tty_driver);
-	put_tty_driver(gs_tty_driver);
+	tty_driver_kref_put(gs_tty_driver);
 	gs_tty_driver = NULL;
 }
 module_exit(userial_cleanup);

drivers/usb/host/xhci-dbgtty.c

···
 	ret = tty_register_driver(dbc_tty_driver);
 	if (ret) {
 		pr_err("Can't register dbc tty driver\n");
-		put_tty_driver(dbc_tty_driver);
+		tty_driver_kref_put(dbc_tty_driver);
 	}
 	return ret;
 }
···
 {
 	if (dbc_tty_driver) {
 		tty_unregister_driver(dbc_tty_driver);
-		put_tty_driver(dbc_tty_driver);
+		tty_driver_kref_put(dbc_tty_driver);
 		dbc_tty_driver = NULL;
 	}
 }

drivers/usb/serial/usb-serial.c

···
 
 exit_bus:
 	pr_err("%s - returning with error %d\n", __func__, result);
-	put_tty_driver(usb_serial_tty_driver);
+	tty_driver_kref_put(usb_serial_tty_driver);
 	return result;
 }
 
···
 	usb_serial_generic_deregister();
 
 	tty_unregister_driver(usb_serial_tty_driver);
-	put_tty_driver(usb_serial_tty_driver);
+	tty_driver_kref_put(usb_serial_tty_driver);
 	bus_unregister(&usb_serial_bus_type);
 	idr_destroy(&serial_minors);
 }

include/linux/tty_driver.h

···
 
 extern struct tty_driver *__tty_alloc_driver(unsigned int lines,
 		struct module *owner, unsigned long flags);
-extern void put_tty_driver(struct tty_driver *driver);
 extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
 extern void tty_driver_kref_put(struct tty_driver *driver);

net/bluetooth/rfcomm/tty.c

···
 	error = tty_register_driver(rfcomm_tty_driver);
 	if (error) {
 		BT_ERR("Can't register RFCOMM TTY driver");
-		put_tty_driver(rfcomm_tty_driver);
+		tty_driver_kref_put(rfcomm_tty_driver);
 		return error;
 	}
 
···
 void rfcomm_cleanup_ttys(void)
 {
 	tty_unregister_driver(rfcomm_tty_driver);
-	put_tty_driver(rfcomm_tty_driver);
+	tty_driver_kref_put(rfcomm_tty_driver);
 }