Re: [REGRESSION] 7.1.6: No sound on MacBook12,1 (Cirrus CS4208) - DAC receives data but speaker silent

On Mon, 10 Aug 2026 10:13:11 +0200,
nqse0035 wrote:
> 
> 
> Hi,
> 
> Regression introduced in: v7.1.5 -> v7.1.6 (tested both; config unchanged)
> 
> Hardware: MacBook9,1 (2016 MacBook 12"), HDA Intel PCH,
> Cirrus Logic CS4208 codec (SSID 106b:0000)
> Kernel: 7.1.5.arch1-2 (works) / 7.1.6.arch1-1 (broken) on Arch Linux
> Audio stack: PipeWire 1.6.8, WirePlumber 0.5.15
> 
> Symptom:
> After upgrading to 7.1.6 and rebooting, the internal speaker is
> completely silent. Volume UI responds, playback apps run, but no
> sound comes out. Reboot does not help (this is NOT the pre-existing
> occasional no-sound-after-boot issue - it is persistent).
> 
> What I verified (all identical between 7.1.5 and 7.1.6):
> - Codec enumerates fine; snd_hda_intel + snd_hda_codec_cs420x load OK
> - PipeWire/WirePlumber up; default sink
> alsa_output.pci-0000_00_1f.3.analog-stereo present and active
> - Mixer controls unmuted (Master 72%, PCM 100%, Line Out 100%)
> - Routing correct: Active Port = analog-output-speaker,
> headphones not available
> - DAC Node 0x02 shows "Converter: stream=1" -> data IS reaching the
> codec, but the speaker amplifier never produces sound
> - dmesg/journalctl: no ALSA/HDA errors at all
> - Codec fixup/autoconfig logs identical between kernels:
> "CS4208: picked fixup for codec SSID 106b:0000",
> line_outs=1 (0x1d) type:speaker, hp_outs=1 (0x10)
> - Verified power_save=0 (our setting) is NOT the cause: reloaded
> module with power_save=10, still silent; and 7.1.5 works with the
> same configuration
> 
> Conclusion:
> A regression between 7.1.5 and 7.1.6 breaks the CS4208 amplifier
> output path. Suspect: the HD-audio pending-IRQ handling rework from
> the 7.1-rc5 cycle (stated to affect "odd machines"), which likely
> changed hda-intel/hda-core behaviour on this platform.
> 
> Workaround: staying on 7.1.5 (pinned). Happy to run tests or
> provide any further debug info.
> 
> #regzbot introduced: v7.1.5..v7.1.6

Through a quick glance, there is no relevant change between v7.1.5 and
v7.1.6.  At best, please do bisect.


thanks,

Takashi