[alsa-devel] No speaker output with kernel 3.15 and later

[Takashi Iwai]

At Mon, 07 Jul 2014 16:34:10 +0100,
Steven Newbury wrote:
> 
> On Tue, 2014-07-01 at 13:54 +0200, Takashi Iwai wrote:
> > At Tue, 01 Jul 2014 12:49:32 +0100,
> > Steven Newbury wrote:
> > >  On Mon, 2014-06-30 at 11:24 +0200, Takashi Iwai wrote:
> > > >  At Sun, 29 Jun 2014 15:09:56 +0100,
> > > >  Steven Newbury wrote:
> > > > >   I sent
> > > > >  Takashi an email mentioning this regression a month ago, and
> > > > >   it's
> > > > >  taken me this long to send this email... :-$
> > > > >   Since updating to
> > > > >  kernel versions >=3.15 I've had no audio from my
> > > > >   laptop speakers.
> > > > >  Earlier versions worked fine.
> > > > >   It's a CLEVO W270EUQ laptop.  The
> > > > >  output mixer device is showing up,
> > > > >   but no sound comes out at any
> > > > >  volume level.
> > > > >   As requested I've attached compressed alsa-info.sh
> > > > >  output for both the
> > > > >   working and non-working cases.
> > > > >   I'm perfectly
> > > > >  willing to test patches etc.
> > > >  Hm, I see no significant difference between 3.14 and 3.15 
> > > > alsa-info.sh
> > > >  outputs, and there's been very little change for VIA codecs 
> > > > between
> > > >  these versions.  So, in short, I have no idea what went wrong.
> > > >  Could you double-check whether it's really a kernel issue?
> > > >  That is, switch between 3.14 and 3.15 and confirm the problem 
> > > > happens
> > > >  only with 3.15.  Also, for testing the sound, try like
> > > >          % aplay -Dplughw -vv foo.wav
> 
> > >  Checked again.
> > >  3.16-rc2: silence
> > >  3.14.3: works fine
> >  
> > Then I'd suggest to bisect between 3.14 and 3.15.
> >  
> >  
> Somewhat surprisingly I ended up here:
> 
> dcb32ecd9a533f47ab652c5c5680bc50a7a822cd is the first bad commit
> 
> commit dcb32ecd9a533f47ab652c5c5680bc50a7a822cd
> Author: Anssi Hannula <anssi.hannula at iki.fi>
> Date:   Tue Apr 8 12:36:42 2014 +0300
> 
>     ALSA: hda - Do not assign streams in reverse order
>     
>     Currently stream numbers are assigned in reverse order.
>     
>     Unfortunately commit 7546abfb8e1f9933b5 ("ALSA: hda - Increment
>     default stream numbers for AMD HDMI controllers") assumed this was not
>     the case (specifically, it had the "old cards had single device only"
>     => "extra unused stream numbers do not matter" assumption), causing
>     non-working audio regressions for AMD Radeon HDMI users.
>     
>     Change the stream numbers to be assigned in forward order.
>     
>     The benefit is that regular audio playback will still work even if the
>     assumed stream count is too high, downside is that a too high stream
>     count may remain hidden.
>     
>     Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77002
>     Reported-by: Christian Güdel <cg at dmesg.ch>
>     Signed-off-by: Anssi Hannula <anssi.hannula at iki.fi>
>     Tested-by: Christian Güdel <cg at dmesg.ch> # 3.14
>     Cc: Alex Deucher <alexander.deucher at amd.com>
>     Signed-off-by: Takashi Iwai <tiwai at suse.de>
> 
> :040000 040000 6ed3a982a9600333b07a42169db5173fa75b8618 b7ff28d00007f988221ba58c9d3f501fdb3a7583 M        sound

Interesting.  Does reverting this commit fix the issue?
Just run "git revert dcb32ecd9a533f47ab652c5c5680bc50a7a822cd", and
test it.


thanks,

Takashi