Comment # 5 on bug 1191247 from Takashi Iwai

(In reply to Andrea P from comment #4)
> (In reply to Takashi Iwai from comment #3)
> > Thanks for quick testing.
> > 
> > Then could you load alsa-info.sh output from the patched kernel after
> > suspend/resume?  Run the script with --no-upload, and use Bugzilla
> > attachment.
> 
> Thank  you. 
> Sorry but I have no idea how to run this script. where is located? so sorry,
> I'm not that expert :D

It's /usr/sbin/alsa-info.sh included in alsa-utils package.  It should have
been already installed.  Just run it as root with --no-upload option, and
attach the generated file to Bugzilla (don't paste, it's big).


> > 
> > - Check whether the problem persists with suspend-to-RAM and suspend-to-disk
> > (hibernate).  I assume you're dealing with the former, right?
> 
> Hibernate it doesn't work on my PC (maybe because I don't have a swap
> partition?).

Right, hibernate works only with a swap (or other dedicated) partition.

> > - Last but not least, check whether re-loading the driver fixes the problem
> > without re-plugging.  You might need to go out of desktop session once,
> > unload snd-usb-audio module and re-load snd-usb-audio module on Linux
> > console.
> 
> Again, so sorry but I don't know how to stop and re-load this module.

OK, then to make things easier:
- Try to boot with a boot option "3"
  This will boot to Linux console without GUI
- Login there, plug USB-audio device, test directly via aplay
    % aplay -Dplughw:XXX foo.wav
  as mentioned in the above.
- Do suspend/resume
    % systemctl suspend
- Check again aplay and confirm the mono output
- Unload / reload the module
    % sudo modprobe -r snd-usb-audio
    % sudo modprobe snd-usb-audio
- Test aplay again