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 <[email protected]> --- drivers/tty/serial/sh-sci.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 9a47cc4f16a2..7c1c0c08459e 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -3063,6 +3063,12 @@ static int sci_probe_single(struct platform_device *dev, return -EINVAL; } + if (!sci_uart_driver.state) { + ret = uart_register_driver(&sci_uart_driver); + if (ret) + return ret; + } + ret = sci_init_single(dev, sciport, index, p, false); if (ret) return ret; @@ -3186,24 +3192,17 @@ 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 -- 2.11.0
