Problems on Apple iBook with ALSA and snd-powermac [2.6.11.5]

Problems on Apple iBook with ALSA and snd-powermac [2.6.11.5]

[Martin Loschwitz]

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Hi folks,

given that the alsa-user-mailinglist has some strange kind of authentication
mechanism, and admin-authorization and whatever, I'm writing this mail to the
LKML (it would have been CCed here anyway).

The current snd-powermac module from ALSA seems to have trouble with modern
Apple iBook computers (and possible other Apple notebooks, but I can't tell
for sure). With 2.6.11.5 and having snd-powermac loaded, playing some sound
results in a very noisy playback; you can only hear that if you turn volume
on the PCM and VOL mixers up to the maximum, and even then, it's very hard 
to hear. After removing snd-powermac and loading the "old" pmac-driver, the
sound playback works just fine.

I have been able to find out that with 2.6.8 (at least with the version that
Debian ships currently), the problem does not appear; snd-powermac does its
job very nicely there. Given that 2.6.11 included some ALSA changes, I just
compiled 2.6.10 on this box and booted it, and had the same problems I have
with snd-powermac on 2.6.11.5.

Is this a known problem and is a fix available for it? If not, what can I do
to help with hunting this bug? I really like ALSA and prefer it over the old
pmac-sound-driver.

-- 
  .''`.   Martin Loschwitz           Debian GNU/Linux developer
 : :'  :  madkiss@madkiss.org        madkiss@debian.org
 `. `'`   http://www.madkiss.org/    people.debian.org/~madkiss/
   `-     Use Debian GNU/Linux 3.0!  See http://www.debian.org/

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Re: Problems on Apple iBook with ALSA and snd-powermac [2.6.11.5]

[Benjamin Herrenschmidt]

On Mon, 2005-03-28 at 01:08 +0200, Martin Loschwitz wrote:
> Hi folks,
> 
> given that the alsa-user-mailinglist has some strange kind of authentication
> mechanism, and admin-authorization and whatever, I'm writing this mail to the
> LKML (it would have been CCed here anyway).
> 
> The current snd-powermac module from ALSA seems to have trouble with modern
> Apple iBook computers (and possible other Apple notebooks, but I can't tell
> for sure). With 2.6.11.5 and having snd-powermac loaded, playing some sound
> results in a very noisy playback; you can only hear that if you turn volume
> on the PCM and VOL mixers up to the maximum, and even then, it's very hard 
> to hear. After removing snd-powermac and loading the "old" pmac-driver, the
> sound playback works just fine.

Have you tried disabling DRC Or increasing the DRC range level ?

> I have been able to find out that with 2.6.8 (at least with the version that
> Debian ships currently), the problem does not appear; snd-powermac does its
> job very nicely there. Given that 2.6.11 included some ALSA changes, I just
> compiled 2.6.10 on this box and booted it, and had the same problems I have
> with snd-powermac on 2.6.11.5.
> 
> Is this a known problem and is a fix available for it? If not, what can I do
> to help with hunting this bug? I really like ALSA and prefer it over the old
> pmac-sound-driver.
> 
-- 
Benjamin Herrenschmidt <benh@kernel.crashing.org>

Re: Problems on Apple iBook with ALSA and snd-powermac [2.6.11.5]

[Lee Revell]

On Mon, 2005-03-28 at 01:08 +0200, Martin Loschwitz wrote:
> Hi folks,
> 
> given that the alsa-user-mailinglist has some strange kind of authentication
> mechanism, and admin-authorization and whatever, I'm writing this mail to the
> LKML (it would have been CCed here anyway).

Still off topic.  ALSA bug reports should be filed here:

https://bugtrack.alsa-project.org/alsa-bug/login_page.php

Lee