[Solved] ALSA problems after world update (No audio)

[gtwrek]

My system uses (just) alsa for sound - I've infrequent, simple sound needs - after configuring ALSA many years ago it was sufficient. All I need is an analog stereo headphone jack to work.
After a recent portage world update, I've got no audio at all from my headset. (I update world ~1 a week - but the audio may have been broken for a few weeks before I even noticed). It was sometime (I think) in the October timeframe that things broke. That said, I didn't see any relevant updates to alsa/audio stuff.

To make sure not a hardware problem - booted into a recent Knoppix Live USB. Sound works fine there.

Back to gentoo:

Checked alsamixer for volumes. That's ok.
Went back into the alsa guide here:
https://wiki.gentoo.org/wiki/ALSA

No help. I've not recompiled my kernel since things broke - with the same kernel I'm still using I had audio working fine in the past. But I'm fine with poking kernel options.
Relevant info:

Code: Select all

% more ~/.asoundrc
defaults.pcm.!card PCH 
defaults.pcm.!device 0
defaults.ctl.!card PCH

Code: Select all

% aplay --list-devices
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC892 Analog [ALC892 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 1: ALC892 Digital [ALC892 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 8: HDMI 2 [DELL U2419H]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: NVidia [HDA NVidia], device 10: HDMI 4 [HDMI 4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Kernel 5.15.32-gentoo-r1

Alsa-info here:
https://pastebin.com/Z1LR9cU8

Any suggestions?

[psycho]

Hi Gtwrek.

I'm using pure ALSA here too and no updates have broken anything. What are using to test the audio? If your hardware's fine (and you know it is, as you've tested it with Knoppix) and you definitely haven't touched your kernel since it was working, it looks like a software issue. If you have a test file like test.wav and

Code: Select all

aplay test.wav

what's the output? Also are you 100% sure your alsamixer levels are all good... you've gone through systematically toggling mutes and other settings and making sure levels are pumped right up...? Everything can look good at first glance while a little toggle somewhere is muted or whatever.

The aplay test will work from a shell (without launching X) if you have one of those bloated desktops that wants to layer its own crap onto everything, and an update has given it an opportunity to do that. If aplay works (reports "Playing WAVE 'test.wav'") but you still don't have audio, and alsamixer's definitely good (and again you're sure the kernel ALSA stuff hasn't been touched, and this exact hardware setup works with other software), I guess you could have a look at the working (Knoppix) ALSA config (check its .asoundrc etc.) for ideas.

[gtwrek]

Thanks for replying.

I maxed out everything in alsamixer. I'm using:

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speaker-test -c 2

To test my headphones. It runs, with normal indications, just no sound:

Code: Select all

% speaker-test -c 2

speaker-test 1.2.7

Playback device is default
Stream parameters are 48000Hz, S16_LE, 2 channels
Using 16 octaves of pink noise
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 2048 to 16384
Period size range from 1024 to 1024
Using max buffer size 16384
Periods = 4
was set period_size = 1024
was set buffer_size = 16384
 0 - Front Left
 1 - Front Right
Time per period = 5.641093

No bloated desktop for me. Manual startx with a fairly basic openbox window manager. Tried aplay as well, no differences in behavior.

[psycho]

Yes, manual startx into openbox is nice and simple... but it's still launching additional stuff that could conceivably be interfering somehow, so it still wouldn't hurt to do your ALSA testing from the console (before startx) just to make absolutely sure it's as silent in the shell as it is in openbox. The output you're getting there is basically identical to what I'm getting (though I'm hearing the static as expected), so speaker-test certainly seems to be doing its job without issues... I wonder if it's a driver problem? I haven't forgotten that you have *not* built a new kernel since it was working, but changes in other packages (linux-firmware, boot managers and so on) could still conceivably affect what's being loaded from your kernel. At least you know, from the working Knoppix audio, that everything's physically wired up as it ought to be, with no damaged hardware.

I've updated this system again today and again nothing's broken: I can even delete my .asoundrc and speaker-test works fine just with the system defaults. It's pure ALSA like yours, but the chipset's ALC221 rather than your ALC892... I'm a bit stumped as to what else could be wrong, if your mixer levels are all up and your hardware's fine and you've confirmed that Knoppix is working fine with the same audio device. It does look like it's most likely an ALSA configuration problem, but I can't think what's wrong, if your .asoundrc is the same on the working setup.

[gtwrek]

Experimented with rebooting and experimenting again from console before starting window manager. Nothing.
Rebooted into Knoppix - things working again. Make all sorts of notes on the sound configuration there, including kernel stuff.
Reboot back into Gentoo. More experiments. Look at kernel settings again. Nothing.
Let it be for a while.

Go back into alsamixer yet again. Tired of the unreadable color scheme (Yellow text on white background. yeah, that's readable). man alsamixer. Ahh "alsamixer -g" uses an actually readable black and white. Levels still look good. "Wait, what's this 'MM' at the bottom of the thermometer code?" Dig through help. "M" to toggle mute. "Can it be this dumb?" I think.... Yep.

Solved, as you suggested psycho it was just alsa "muting", but I just wasn't seeing this in the alsamixer UI as a separate control from the thermometer setting. 4 months of no audio over this dumb setting that I didn't see.

[psycho]

Don't worry, it's not dumb: thanks to alsamixer's UI it's one of the most easily made mistakes. That's why I asked "you've gone through systematically toggling mutes...?", because so many of us have experienced this thing of wasting time trying to fix audio issues when it's just that our eyes have been drawn to the high levels and have overlooked the little mute toggles (or another way it can happen is that the relevant setting is named in a way that suggests we don't need it, hence "systematically" rather than just unmuting what we assume is necessary). On the bright side it won't ever happen again: the next time you're not getting any sound, alsamixer's little MM toggles will jump out at you like flashing neon