Re: CMI973, patch and alsa release

[Takashi Iwai <tiwai@suse.de>]

At Mon, 2 Feb 2004 09:06:37 +0100 (CET),
Jaroslav wrote:
> 
> On Sun, 1 Feb 2004, Davodet Olivier wrote:
> 
> > Hello,
> > 
> > My config :
> > 
> > Biostar IdeQ 200T with an onboard C-Media CMI9739A 6-Channel AC'97 CODEC
> > Mandrake 9.2 : kernel 2.6.1 with alsa 1.0.1
> > (kernel-smp-2.6.1.1mdk-1-1mdk) and alsa lib 0.9.6
> > 
> > I use the snd-intel8x0 module.
> > 
> > This module does not work very well with this chipset. In fact you can't use
> > PCM. When you launch xmms the sound plays but you can't change the
> > volume...
> > 
> > In the alsa-devel mailing-list I found a patch by C.L. Thien (from 
> > cmedia) for the alsa 1.0.rc2.
> > 
> > I updated my kernel source with this patch, recompiled all and installed the
> > new sound modules.
> > 
> > And now all works fine, I can change the sound volume in xmms, mute, unmute,
> > all works ok ! (except the known bug with quake 3 : the sound loops when you
> > enter in a map and quake3 freezes...)
> > 
> > Do you think this patch can be included by the alsa team in an official 
> > release ?
> 
> No. This patch is unacceptable for us.

well, let me clarify more the problems.

- the patch copies the whole audio data with the software
  attenuation.  we don't want this in the kernel context.
  this should be the job in the user-space, pereferrably in alsa-lib.

- the patch introduces float calculation.
  it's not allowed at all in the kernel code.


the control of ac97 mic and line sharing is a good point.
the similar thing can be implemented more easily by the alsa-lib's
hook plugin, though.


Takashi


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