Re: No speaker output with kernel 3.15 and later

[Steven Newbury <steve@snewbury.org.uk>]

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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@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@dmesg.ch>
    Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
    Tested-by: Christian Güdel <cg@dmesg.ch> # 3.14
    Cc: Alex Deucher <alexander.deucher@amd.com>
    Signed-off-by: Takashi Iwai <tiwai@suse.de>

:040000 040000 6ed3a982a9600333b07a42169db5173fa75b8618 b7ff28d00007f988221ba58c9d3f501fdb3a7583 M        sound


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