Re: [PATCH] serial: samsung: Remove hard-coded major/minor numbers

From: Alexander Shiyan
Date: Fri Dec 27 2013 - 01:43:45 EST


Hello.
> On Fri, Dec 27, 2013 at 12:00:20PM +0530, Tushar Behera wrote:
> > On 27 December 2013 10:48, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > > On Fri, Dec 27, 2013 at 10:37:28AM +0530, Tushar Behera wrote:
> > >> The hard-coded values clash with the values set for amba-pl011 serial
> > >> driver. Because of this there is no serial output on Samsung boards
> > >> if amba-pl011 is enabled alongwith samsung-serial driver.
> > >>
> > >> Remove the hardcoded values and let the framework decide on
> > >> appropriate major/minor number. This is required for multi-platform
> > >> development work on Exynos platform.
> > >>
> > >> Signed-off-by: Tushar Behera <tushar.behera@xxxxxxxxxx>
...
> > >> #define S3C24XX_SERIAL_NAME "ttySAC"
> > >> -#define S3C24XX_SERIAL_MAJOR 204
> > >> -#define S3C24XX_SERIAL_MINOR 64
> > >>
> > >> /* macros to change one thing to another */
> > >>
> > >> @@ -951,8 +949,6 @@ static struct uart_driver s3c24xx_uart_drv = {
> > >> .nr = CONFIG_SERIAL_SAMSUNG_UARTS,
> > >> .cons = S3C24XX_SERIAL_CONSOLE,
> > >> .dev_name = S3C24XX_SERIAL_NAME,
> > >> - .major = S3C24XX_SERIAL_MAJOR,
> > >> - .minor = S3C24XX_SERIAL_MINOR,
> > >
> > > Doesn't this break existing systems and configurations that are
> > > expecting 204:64 as the location of this serial port?
> > >
> >
> > I tested this on Exynos4210-Origen, Exynos5250-Arndale board, it works
> > fine there. I haven't tested on any older boards.
>
> How did it work? You are relying on some userspace tools to do this
> properly, right? What about systems without those specific tools?

Can this issue be resolved by using MODULE_ALIAS_CHARDEV()
in the driver code?

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