From 352b92664549e9dcdded742424a96aac9a0dbb40 Mon Sep 17 00:00:00 2001 From: Sjoerd Simons Date: Thu, 20 Apr 2017 14:13:01 +0200 Subject: [PATCH] serial: sh-sci: Move uart_register_driver call to device probe uart_register_driver call binds the driver to a specific device node through tty_register_driver call. This should typically happen during device probe call. In a multiplatform scenario, it is possible that multiple serial drivers are part of the kernel. Currently the driver registration fails if multiple serial drivers with overlapping major/minor numbers are included. Signed-off-by: Sjoerd Simons Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 21b06cf1f15b..54de985ad214 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2962,6 +2962,7 @@ static inline int sci_probe_earlyprintk(struct platform_device *pdev) static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized"; +static DEFINE_MUTEX(sci_uart_registration_lock); static struct uart_driver sci_uart_driver = { .owner = THIS_MODULE, .driver_name = "sci", @@ -3090,6 +3091,16 @@ static int sci_probe_single(struct platform_device *dev, return -EINVAL; } + mutex_lock(&sci_uart_registration_lock); + if (!sci_uart_driver.state) { + ret = uart_register_driver(&sci_uart_driver); + if (ret) { + mutex_unlock(&sci_uart_registration_lock); + return ret; + } + } + mutex_unlock(&sci_uart_registration_lock); + ret = sci_init_single(dev, sciport, index, p, false); if (ret) return ret; @@ -3213,24 +3224,17 @@ static struct platform_driver sci_driver = { static int __init sci_init(void) { - int ret; - pr_info("%s\n", banner); - ret = uart_register_driver(&sci_uart_driver); - if (likely(ret == 0)) { - ret = platform_driver_register(&sci_driver); - if (unlikely(ret)) - uart_unregister_driver(&sci_uart_driver); - } - - return ret; + return platform_driver_register(&sci_driver); } static void __exit sci_exit(void) { platform_driver_unregister(&sci_driver); - uart_unregister_driver(&sci_uart_driver); + + if (sci_uart_driver.state) + uart_unregister_driver(&sci_uart_driver); } #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE -- 2.39.5