Re: [PATCH] x86 - Make CONFIG_OLPC dependent on CONFIG_MGEODE_LX

[Takashi Iwai <tiwai@suse.de>]

At Sun, 9 Nov 2008 20:17:10 -0800,
Andres Salomon wrote:
> 
> On Tue, 11 Nov 2008 15:04:06 +0100
> Ingo Molnar <mingo@elte.hu> wrote:
> 
> > 
> > * Takashi Iwai <tiwai@suse.de> wrote:
> > 
> > > At Tue, 11 Nov 2008 14:53:06 +0100,
> > > Ingo Molnar wrote:
> > > > 
> > > > 
> > > > * Takashi Iwai <tiwai@suse.de> wrote:
> > > > 
> > > > > At Tue, 11 Nov 2008 13:54:02 +0100,
> > > > > Ingo Molnar wrote:
> > > > > > 
> > > > > > 
> > > > > > * Takashi Iwai <tiwai@suse.de> wrote:
> > > > > > 
> > > > > > > The OLPC-specpfic codes require geode_gpio_*() functions
> > > > > > > although these functions are defined only with
> > > > > > > CONFIG_MGEODE_LX=y. Add a proper dependency to fix build
> > > > > > > errors.
> > > > > > > 
> > > > > > > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > > > > > 
> > > > > > hm, could you please send a .config that shows the build
> > > > > > errors?
> > > > > 
> > > > > Here it is.  It's for today's linux-next.
> > > > 
> > > > hm, which tree did that build failure in linux-next originate
> > > > from? Your config builds fine here with the latest x86 tree.
> > > 
> > > Ah, sorry, forgot to mention that the build error comes from the
> > > latest ALSA code.  It contains an OLPC-specific code that is enabled
> > > via CONFIG_OLPC like:
> > > 
> > > 	snd-cs5535audio-$(CONFIG_OLPC) += cs5535audio_olpc.o
> > > 
> > > where this includes geode_gpio_*() calls.
> > > 
> > > Of course, I can add an if in Makefile or create a new Kconfig, but 
> > > since asm/olpc.h itself includes asm/geode.h and contains 
> > > geode_gpio*() calls, it would be a proper fix to make CONFIG_OLPC 
> > > dependent on geode.
> > 
> > ah, okay, agreed - i was worried whether this is something affecting 
> > v2.6.28 or slipping through our testing before commits hit linux-next.
> > 
> > I've queued up your fix in tip/x86/kconfig, thanks Takashi!
> > 
> > 	Ingo
> 
> 
> This works for now (though it's probably going to anger some people who
> are trying to make generic distro kernels),

Well, no reason to get angry.  It can't be generic as is now because
of geode-specific features.

> but what we really need to
> do is to make geode_gpio* defined even when we're not specifically
> building with MGEODE_LX.  I'm not sure how best to do that, but the
> answer probably includes using the generic x86 gpio api.

OTOH, if geode-specific functions are silently ignored, e.g. via dummy
inline functions, the resultant kernel/driver won't work properly
although you don't get any build errors with CONFIG_OLPC=y.  With the
explicit option, you can know at least something has to be enabled
properly...


thanks,

Takashi