[alsa-devel] [PATCH] wss_lib: snd_wss_calibrate_mute improvement

[krzysztof.h1 at poczta.fm]

> At Mon, 18 Aug 2008 10:50:15 +0200,
> Rene Herman wrote:
> > 
> > On 17-08-08 22:38, Krzysztof Helt wrote:
> > 
> > > From: Krzysztof Helt <krzysztof.h1 at wp.pl>
> > > 
> > > Mute sound by setting mute bit without
> > > setting volume to 0. It makes both source code
> > > and binary shorter.
> > > 
> > > Signed-off-by: Krzysztof Helt <krzysztof.h1 at wp.pl>
> > 
> > Grmmbbled-over-by: Rene Herman <rene.herman at gmail.com>
> > 
> > This should be safe and the current function indeed generates crap code
> 
> > but in the sense of always expecting the worst broken hardware variants
> 
> > to be out there I must say I'd rather have seen that GCC were beter. But
> 
> > yes, sure.
> 
> Yeah, the slightest concern is the intention of using 0x80 there.
> If this patch was already tested on some real hardwares (and I guess
> it should work), I'm willing to apply it.  Krzystof, was this tested
> on your machines?
> 

I have tested it only on cs4236 (inside laptop) and opti931 I have in the old PC at the moment. If you want I can retest on more hardware.

The second check I noticed that for some registers the volume is defined as gain (so 0 is the least audible) and for some (CS4231_MONO_CTRL, CS4231_LEFT/RIGHT_OUTPUT) is defined as attentuation (the 0 is the most audible). In two cases, the old code set volume to the loudest and mute it with mute bit, probably the opposite what was intended.

It is not a crucial patch. You may drop it.

Regards,
Krzysztof

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