| Message ID | 20211127223253.19098-6-semen.protsenko@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | soc: samsung: Add USIv2 driver | expand |
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
On Mon, 29 Nov 2021 at 10:52, Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> wrote: > > 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. > I guess that's already taken care of in samsung_serial_remove(): it's doing uart_remove_one_port(), which in turn does unregister_console(). So I don't think anything extra should be done on module exit. Or I'm missing something? That case (unload/load) actually doesn't work well in my case: serial console doesn't work after doing "modprobe -r samsung_tty; modprobe samsung_tty" (but it works fine e.g. in case of i2c_exynos5 driver). Not sure what is wrong, but I can see that my board keeps running (heartbeat LED is still blinking). Not even sure if that use case (unload/load) was ever functional before. Anyway, please let me know if you think something should be done about this particular patch. Right now I don't see anything missing. > > + > > + 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
On Mon, 29 Nov 2021 at 22:18, Sam Protsenko <semen.protsenko@linaro.org> wrote: > > On Mon, 29 Nov 2021 at 10:52, Krzysztof Kozlowski > <krzysztof.kozlowski@canonical.com> wrote: > > > > 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. > > > > I guess that's already taken care of in samsung_serial_remove(): it's > doing uart_remove_one_port(), which in turn does unregister_console(). > So I don't think anything extra should be done on module exit. Or I'm > missing something? > > That case (unload/load) actually doesn't work well in my case: serial > console doesn't work after doing "modprobe -r samsung_tty; modprobe > samsung_tty" (but it works fine e.g. in case of i2c_exynos5 driver). > Not sure what is wrong, but I can see that my board keeps running > (heartbeat LED is still blinking). Not even sure if that use case > (unload/load) was ever functional before. > > Anyway, please let me know if you think something should be done about > this particular patch. Right now I don't see anything missing. > ...But I'll actually add proper error path handling in samsung_serial_init(), i.e. unregister console if platform_driver_register() fails. And I'll add the same console unregister in samsung_serial_exit(), just in case. > > > + > > > + 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
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; + + 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 /*
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(-)