Re: [PATCH 5/8] tty: serial: samsung: Enable console as module

Krzysztof Kozlowski
2021-11-29T08:54:21Z

On 27/11/2021 23:32, Sam Protsenko wrote:
> Enable serial driver to be built as a module. To do so, init the console
> support on driver/module load instead of using console_initcall().
>
> This is needed for proper support of USIv2 driver (which can be built as
> a module, which in turn makes SERIAL_SAMSUNG be a module too). It also
> might be useful for Android GKI modularization efforts.
>
> Inspired by commit 87a0b9f98ac5 ("tty: serial: meson: enable console as
> module").
>
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> ---
> drivers/tty/serial/Kconfig | 2 +-
> drivers/tty/serial/samsung_tty.c | 21 +++++++++++++++++++--
> 2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index fc543ac97c13..0e5ccb25bdb1 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -263,7 +263,7 @@ config SERIAL_SAMSUNG_UARTS
>
> config SERIAL_SAMSUNG_CONSOLE
> bool "Support for console on Samsung SoC serial port"
> - depends on SERIAL_SAMSUNG=y
> + depends on SERIAL_SAMSUNG
> select SERIAL_CORE_CONSOLE
> select SERIAL_EARLYCON
> help
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index f986a9253dc8..92a63e9392ed 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -1720,10 +1720,10 @@ static int __init s3c24xx_serial_console_init(void)
> register_console(&s3c24xx_serial_console);
> return 0;
> }
> -console_initcall(s3c24xx_serial_console_init);
>
> #define S3C24XX_SERIAL_CONSOLE &s3c24xx_serial_console
> #else
> +static inline int s3c24xx_serial_console_init(void) { return 0; }
> #define S3C24XX_SERIAL_CONSOLE NULL
> #endif
>
> @@ -2898,7 +2898,24 @@ static struct platform_driver samsung_serial_driver = {
> },
> };
>
> -module_platform_driver(samsung_serial_driver);
> +static int __init samsung_serial_init(void)
> +{
> + int ret;
> +
> + ret = s3c24xx_serial_console_init();
> + if (ret)
> + return ret;

This will trigger warns on module re-loading, won't it? Either suppress
unbind or cleanup in module exit.

> +
> + return platform_driver_register(&samsung_serial_driver);
> +}
> +
> +static void __exit samsung_serial_exit(void)
> +{
> + platform_driver_unregister(&samsung_serial_driver);
> +}
> +
> +module_init(samsung_serial_init);
> +module_exit(samsung_serial_exit);
>
> #ifdef CONFIG_SERIAL_SAMSUNG_CONSOLE
> /*
>

Best regards,
Krzysztof