Re: [v3 PATCH 7/9] watchdog/at91sam9_wdt: Use module_platform_driver()

[Fabio Porcedda]

On Sat, Jan 5, 2013 at 3:38 AM, Wenyou Yang <wenyou.yang@xxxxxxxxx> wrote:
> Using module_platform_driver() replaces module_init() and module_exit()
> and makes the code simpler.
>
> Remove '__init' annotation from the function 'at91wdt_probe'
> since the driver becomes hot-plug aware now.
>
> Signed-off-by: Wenyou Yang <wenyou.yang@xxxxxxxxx>
> Cc: wim@xxxxxxxxx
> Cc: linux-watchdog@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
>  drivers/watchdog/at91sam9_wdt.c |   16 +++-------------
>  1 file changed, 3 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
> index 94be9d6..7c13dda 100644
> --- a/drivers/watchdog/at91sam9_wdt.c
> +++ b/drivers/watchdog/at91sam9_wdt.c
> @@ -204,7 +204,7 @@ static struct watchdog_device at91wdt_wdd = {
>         .ops = &at91wdt_ops,
>  };
>
> -static int __init at91wdt_probe(struct platform_device *pdev)
> +static int at91wdt_probe(struct platform_device *pdev)
>  {
>         struct at91wdt_drvdata *driver_data;
>         struct resource *r;
> @@ -273,6 +273,7 @@ MODULE_DEVICE_TABLE(of, at91_wdt_dt_ids);
>  #endif
>
>  static struct platform_driver at91wdt_driver = {
> +       .probe          = at91wdt_probe,
>         .remove         = __exit_p(at91wdt_remove),
>         .driver         = {
>                 .name   = "at91_wdt",
> @@ -281,18 +282,7 @@ static struct platform_driver at91wdt_driver = {
>         },
>  };
>
> -static int __init at91sam_wdt_init(void)
> -{
> -       return platform_driver_probe(&at91wdt_driver, at91wdt_probe);
> -}
> -
> -static void __exit at91sam_wdt_exit(void)
> -{
> -       platform_driver_unregister(&at91wdt_driver);
> -}
> -
> -module_init(at91sam_wdt_init);
> -module_exit(at91sam_wdt_exit);
> +module_platform_driver(at91wdt_driver);
>
>  MODULE_AUTHOR("Renaud CERRATO <r.cerrato@xxxxxxxxxxxxxxxxxxx>");
>  MODULE_DESCRIPTION("Watchdog driver for Atmel AT91SAM9x processors");
> --
> 1.7.9.5
>
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The module_platform_driver isn't a substitute of platform_driver_probe,
because module_platform_driver  use platform_driver_register/unregister.
Using that macro we lose the advantage of platform_driver_probe,
as stated in:

https://lkml.org/lkml/2012/1/10/335
On Tue, Jan 10, 2012 at 21:47, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> [...]
>Still, setting up platform_driver.probe and removing __init from all probe
>functions is not the right thing to do, as this make (non-__init) kernel code
>size bigger, while none of these devices are hotpluggable and thus cannot
>appear after bootup. That's why we have platform_driver_probe() in the
>first place. So I think all of this should be reverted for non-hotpluggable
>drivers.
> [...]

Best regards

--
Fabio Porcedda
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