Re: [PATCH] [media] smiapp: make PM functions as __maybe_unused

From: Arnd Bergmann
Date: Thu Oct 27 2016 - 03:43:41 EST


On Thursday, October 27, 2016 10:28:18 AM CEST Sakari Ailus wrote:
>
> On Wed, Oct 26, 2016 at 10:38:01PM +0200, Arnd Bergmann wrote:
> > The rework of the PM support has caused two functions to
> > be orphaned when CONFIG_PM is disabled:
> >
> > media/i2c/smiapp/smiapp-core.c:1352:12: error: 'smiapp_power_off' defined but not used [-Werror=unused-function]
> > media/i2c/smiapp/smiapp-core.c:1206:12: error: 'smiapp_power_on' defined but not used [-Werror=unused-function]
> >
> > This changes all four PM entry points to __maybe_unused and
> > removes the #ifdef markers for consistency. This avoids the
> > warnings even when something changes again.
> >
> > Fixes: cbba45d43631 ("[media] smiapp: Use runtime PM")
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> The power-on sequence is in fact mandatory as it involves writing the
> initial configuration to the sensor as well.
>
> Instead, I believe the correct fix is to make the driver depend on
> CONFIG_PM.

(adding linux-pm list)

That would be a rather unusual dependency, though it's possible that
a lot of drivers in fact need it but never listed this explictly in
Kconfig.

What do other drivers do that need to have their runtime_resume
function called at probe time when CONFIG_PM is disabled?

Arnd