There was a similar bug in the past (Bug 217440), which was fixed for this laptop. (I believe the code path is for ALC256, see below.) The same issue is occurring again as of kernel v.6.12.2. The symptoms are very similar - initially audio works but after a warm reboot, the audio completely disappears until the computer is powered off (there is no audio output at all). The issue is also related by caused by a different change now. By bisecting different kernel versions, I found that reverting cc3d0b5dd989d3238d456f9fd385946379a9c13d in patch_realtek.c ( see https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/sound/pci/hda/patch_realtek.c?h=v6.12.2&id=4ed7f16070a8475c088ff423b2eb11ba15eb89b6 ) restores the sound and it works fine after the reboot.
Created attachment 308113 [details] Log file (dmesg) - initial boot and after warm boot
Just to clarify, in the last two lines after warm reboot: [ 9.594956] hdaudio hdaudioC1D0: no AFG or MFG node found [ 9.594965] snd_hda_intel 0000:03:00.6: no codecs initialized
Could you run alsa-info.sh to dump codec info? Please do ==> echo 1 > /sys/module/snd_hda_codec/parameters/dump_coef before do alsa-info.sh.
Created attachment 308121 [details] alsa-info output for the regression (first boot with audio)
Created attachment 308122 [details] alsa-info output for the regression (warm reboot WITHOUT audio)
Created attachment 308123 [details] alsa-info output for the reverted change (first boot with audio)
Created attachment 308124 [details] alsa-info output for the reverted change (warm reboot with audio)
Added alsa-info outputs: 1. the original code with the regression (kernel v6.14, standard with Ubuntu 25.04) 2. the reverted change (kernel v6.15rc5, compiled)
Kailiang, I added alsa-info outputs to https://bugzilla.kernel.org/show_bug.cgi?id=220109 (see attachments for both the regression and reverted changes) by following your instructions. Please let me know if there is any other information you need. Thanks, Ruslan On Tuesday, May 13, 2025 at 02:30:17 AM EDT, <bugzilla-daemon@kernel.org> wrote: https://bugzilla.kernel.org/show_bug.cgi?id=220109 Kailiang Yang (kailang@realtek.com) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |kailang@realtek.com --- Comment #3 from Kailiang Yang (kailang@realtek.com) --- Could you run alsa-info.sh to dump codec info? Please do ==> echo 1 > /sys/module/snd_hda_codec/parameters/dump_coef before do alsa-info.sh.