Re: 2.6.25-mm1 (snd-pcsp causes driver conflict)

[Takashi Iwai <tiwai@suse.de>]

At Mon, 21 Apr 2008 21:44:33 +0400,
Stas Sergeev wrote:
> 
> Hello.
> 
> Takashi Iwai wrote:
> > [Added snd-pcsp author to Cc]
> Thanks.
> 
> > Seems that snd-pcsp registers as "pcspkr", which is identical with
> > input pc-speaker driver.  Does the patch below fix the problem?
> Actually it does not. The reason is that
> then it fails to match the platform device,
> which is created in arch/x86/kernel/pcspeaker.c,
> with the name of "pcspkr".

Hm, the hardcoded string is no good thing.
It should be defined in the common header if it's used in multiple
places.

I'm not 100% certain whether restrictng this in Kconfig is the correct
fix.  Basically this doesn't stop building both drivers.  In theory,
we can switch them dynamically.

But, it's the easiest way to avoid unnecessary bugs right now, so
let's merge it.

> But we already had the patch for that in an
> alsa tree, it probably got forgotten. Here
> it is:
> http://hg-mirror.alsa-project.org/alsa-driver/raw-file/90eeee75052f/utils/patches/pcsp-kernel-2.6.22-01.diff

Err, no, this wasn't merged to sound git tree because apparently the
patch is to 2.6.22 and you didn't resubmit it...

> Also attaching it here.
> It simply disables the pcspkr driver in
> Kconfig. snd-pcsp has the copy of that
> driver, so that only one driver would
> drive the device.
> 
> Does that fix look good? (presumably acked
> by Takashi, otherwise the patch wouldn't
> be in an alsa tree)

No, I gave no ACK yet.  The alsa-driver tree is our playground, and
the patch merged to that tree doesn't mean that I approved it for
linux-kernel merge.

> diff -urN linux-2.6.24/drivers/input/misc/Kconfig linux-2.6.24-pcsp-kern/drivers/input/misc/Kconfig
> --- linux-2.6.24/drivers/input/misc/Kconfig	2008-01-27 16:13:43.000000000 +0300
> +++ linux-2.6.24-pcsp-kern/drivers/input/misc/Kconfig	2008-01-27 17:03:31.000000000 +0300
> @@ -14,7 +14,8 @@
>  
>  config INPUT_PCSPKR
>  	tristate "PC Speaker support"
> -	depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
> +	depends on (ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || \
> +		PPC_PSERIES) && SND_PCSP=n

I'd rather add a new line with a single "depends on SND_PCSP=n".
You see a clear difference in the art of dependencies, one for
architectures and one for driver-specific.


thanks,

Takashi