Re: [PATCH 10/10] drivers: misc: use module_platform_driver_probe()

[Sascha Hauer <s.hauer@pengutronix.de>]

On Thu, Mar 14, 2013 at 01:58:05PM +0000, Arnd Bergmann wrote:
> On Thursday 14 March 2013, Fabio Porcedda wrote:
> > This patch converts the drivers to use the
> > module_platform_driver_probe() macro which makes the code smaller and
> > a bit simpler.
> > 
> > Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > ---
> >  drivers/misc/atmel_pwm.c  | 12 +-----------
> >  drivers/misc/ep93xx_pwm.c | 13 +------------
> >  2 files changed, 2 insertions(+), 23 deletions(-)
> 
> The patch itself seems fine, but there are two issues around it:
> 
> * The PWM drivers should really get moved to drivers/pwm and converted to the new
>   PWM subsystem. I don't know if Hartley or Hans-Christian have plans to do
>   that already.
> 
> * Regarding the use of module_platform_driver_probe, I'm a little worried about
>   the interactions with deferred probing. I don't think there are any regressions,
>   but we should probably make people aware that one cannot return -EPROBE_DEFER
>   from a platform_driver_probe function.

I'm worried about this aswell. I think platform_driver_probe shouldn't
be used anymore. Even if a driver does not explicitly make use of
-EPROBE_DEFER, it leaks in very quickly if a driver for example uses a
regulator and just returns the error value from regulator_get.

Sascha

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