On Sunday, 3 January 2021 15:59:49 GMT Dr Rainer Woitok wrote: > Greetings, > > immediately after a reboot I can clearly hear the white noise created by > executing > > $ aplay /usr/share/sounds/alsa/Noise.wav > Playing WAVE '/usr/share/sounds/alsa/Noise.wav' : Signed 16 bit Little > Endian, Rate 48000 Hz, Mono $ > > and the "lsmod" command lists quite a few loaded sound modules. Howev- > er, after resuming from hibernation the same "aplay" command still pro- > duces the same line on standard output, returns the same exit code of 0, > but does not produce any sound. And the "lsmod" command still lists the > same loaded modules. > > Anybody having a clue what's happening here? > > And while we are at it: At > > https://wiki.gentoo.org/wiki/Kernel/Gentoo_Kernel_Configuration_Guide > > the authors flatly state "Note that ALSA is an exception to the suggest- > ed scheme of not building things as modules: ALSA is actually much easi- > er to configure when the components are modular." without giving any > further expanation. What precisely am I giving away when I build the > ALSA stuff directly into the kernel? > > Sincerely, > Rainer
It used to be the case modules were probed/reloaded by 'alsactl init' when initialising the audio card. If built in the kernel binary the command couldn't do this. Troubleshooting required monitoring responses and errors as the modules were being loaded and consequently the devs were not very forthcoming with solutions, unless you had your alsa drivers compiled as modules. I had a laptop a long time ago, which I had to reboot into MSWindows to get the audio to work again. Using alsamixer and alsactl in Linux would not wake up the card, no matter what I tried. One day this problem went away after a kernel update, so I attributed it to a buggy linux audio driver. Some modules show power saving features with 'modinfo', which may alter the card's behaviour if they can be switched off. I suggest you use alsactl init before and after and compare the output between a working and non-working state, to try to isolate the problem.
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