Fwd: No sound from monitor speakers unless snd_hda_codec_realtek is inserted before snd_hda_intel

[Bagas Sanjaya]

Hi,

I notice a bug report on Bugzilla [1]. Quoting from it:

> I have an Asus Pro B550M-C/CSM motherboard, which uses a Realtek ALC887-VD, and a monitor (with speakers) plugged in via DisplayPort. On booting normally, I get no sound from the monitor speakers (other sound outputs like USB or bluetooth headphones work fine).
> 
> I have found two workarounds for getting the monitor sound working:
> 1. rmmod snd_hda_intel && modprobe snd_hda_intel
> 2. ensure that snd_hda_codec_realtek is inserted before snd_hda_intel (e.g. by adding `softdep snd_hda_intel pre: snd_hda_codec_realtek` in modprobe.d)
> 
> Notably, timing does not seem to be an issue: even if snd_hda_intel is blacklisted from loading at boot, it will not work when it is loaded unless is is unloaded and loaded again or snd_hda_codec_realtek is loaded first.
> 
> This is not a recent regression - it has been happening as long as I have had the hardware (since at least late 2021).
> 
> Since it's not clear which is more useful, I am attaching two runs of alsa-info.sh - one is from a normal boot with sound not working, and the other is after running rmmod snd_hda_intel && modprobe snd_hda_intel with sound working.

See Bugzilla for the full thread and alsa-input output on both working
and buggy cases.

AFAIK, it looks like module dependency issue.

Thanks.

[1]: https://bugzilla.kernel.org/show_bug.cgi?id=218027

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