[alsa-devel] [REGRESSION] 4.1-rc4: Sound muted after boot

[Takashi Iwai]

At Thu, 21 May 2015 10:53:46 +0200,
Martin Steigerwald wrote:
> 
> Am Donnerstag, 21. Mai 2015, 06:28:24 schrieb Takashi Iwai:
> > At Wed, 20 May 2015 16:31:55 +0200,
> > 
> > Martin Steigerwald wrote:
> > > Hello!
> > > 
> > > On ThinkPad T520 (Intel Sandybridge) with 4.14-rc4 + two BTRFS patches
> > > and one Intel P-State debug patch I have no sound output on internal
> > > Intel HD audio codec.
> > > 
> > > According to ThinkPad T520 LED with striked-through speaker the loud
> > > speaker is in disabled state. Also KDE´s Phonon says a soundcard is
> > > missing. In alsa-mixer I see nothing as MM for muted. If I press the
> > > key next to the LED I get a notification on the desktop that loud
> > > speaker has been enabled / disabled, but the LED still is on for it
> > > being disabled.
> > > 
> > > I do not hear anything in Amarok or with aplay. alsa-mixer sound volumes
> > > are 100 for master and PCM. I also tried with disabling "Auto-Mute
> > > Mod", but still no sound.
> > > 
> > > When I reboot and in BIOS or GRUB press the key then the LED toggles
> > > state.
> > > 
> > > When I reboot into Linux 4.0.1 sound is working fine and loud speaker
> > > disabled LED is toggled off, so I bet this is a regression 4.1-rc4
> > > compared to 4.0.1.
> > 
> > Please run alsa-info.sh at both working and non-working cases (with
> > old and new kernels), and attach the outputs. Run the script with
> > --no-upload option.
> 
> All attached.
> 
> I also have full dmesg outputs available in case it is needed.
>  
> > Also, such a problem is rather the device permissions problem.
> > Check the device permissions of /dev/snd/* files (also check getfacl
> > /dev/snd/*, too).
> 
> If its a permissions problem, why does it happen with 4.1-rc4, but not with 
> 4.0.1 oder any earlier kernels?

I wanted to mean it's rather "often" a permission problem.  Not
necessarily your case, but still worth to check.

The mute LED behavior change is because of the new control added
recently.  You seem to have changed the value to "On" while the
default should be "Follow Master".  This explains the difference of
behavior from 4.0.  It's no regression but manual misconfiguration by
user.  In this mode, LED has no connection with the sound output at
all.

Other than that, no different is seen in the hardware level.  The
codec registers show all same values.  That is, from the driver POV,
the sound should work.  (Though, you set "Disabled" to "Auto-Mute
Mode" control which looks rather weird.) 

So, revert "Mute-LED Mode" control to "Follow Master".  It can be done
via alsamixer, amixer or whatever.  Then check whether the sound
works again.  Check also from the headphone, too.


Takashi