[PATCH 2/3] staging: bcm2835-audio: select BCM2835_VCHIQ rather then depending on it.

[Michael Zoran]

On Tue, 2017-02-28 at 21:18 +0100, Stefan Wahren wrote:
> > Michael Zoran <mzoran at crowfest.net> hat am 28. Februar 2017 um
> > 19:49 geschrieben:
> > 
> > 
> > Change the audio's dependency on BCM2835_VCHIQ to a select.
> > 
> > Signed-off-by: Michael Zoran <mzoran at crowfest.net>
> > ---
> >  drivers/staging/vc04_services/bcm2835-audio/Kconfig | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/staging/vc04_services/bcm2835-audio/Kconfig
> > b/drivers/staging/vc04_services/bcm2835-audio/Kconfig
> > index b2e6d90ef1cb..479c9e3ace11 100644
> > --- a/drivers/staging/vc04_services/bcm2835-audio/Kconfig
> > +++ b/drivers/staging/vc04_services/bcm2835-audio/Kconfig
> > @@ -1,7 +1,8 @@
> >  config SND_BCM2835
> >          tristate "BCM2835 Audio"
> > -        depends on ARCH_BCM2835 && BCM2835_VCHIQ && SND
> > +        depends on ARCH_BCM2835 && SND
> >          select SND_PCM
> > +	select BCM2835_VCHIQ
> >          help
> >            Say Y or M if you want to support BCM2835 built in audio
> >  
> 
> AFAIK "depends on" is perferred instead of "select", because it's
> causes less issues. Please explain in the commit messages instead of
> the cover letter why this patch and patch 3 is necessary.

Actually, when I was posting a very small fix to the vc4 driver to the
DRM aliases, I saw some very, very pointed words by Linus during the
4.11 merge directed at someone that used depends when he believed they
should have used select. So it isn't clear exactly what the guidance is
on that.

My understanding is that the issues with select happens if the item
being selected has dependencies itself.  Due to limitations of the
config system, it's possible to select something that can't have it's
dependencies satisfied. In this case BCM2835_VCHIQ doesn't have any
dependencies itself since I moved those to the top menu item.

Let me think about a good way to word this in the commit message.