More than a few Phoronix readers have written in that have been early adopters to the Linux 6.1 kernel released as stable earlier this month and now finding their HDMI audio outputs no longer working. Fortunately, the issue has been sorted out by upstream developers and a fix is on the way.

It turns out a recent refactoring to the ALSA HDA/HDMI driver code for using only dynamic PCM device allocation ended up breaking the AMD hardware support. This change was only merged during the Linux 6.1 merge window so only Linux 6.1 and the early Linux 6.2 development state is affected by this AMD HDMI audio regression.

Additionally, the issue has been analyzed as only affecting the HD audio HDMI codec driver for AMD/ATI hardware when using PulseAudio or PipeWire. If you are using direct audio output via ALSA raw access, that isn't affected by this Linux 6.1 regression.

Details on this recent HD-audio HDMI codec driver refactoring that broke the HDMI audio support for AMD can be found via this commit . Linux sound subsystem maintainer Takashi Iwai of SUSE picked up the patch today for his "for-linus" stable branch and should be submitting it shortly for picking up in Linux Git and then back-porting to the Linux 6.1 stable series for an upcoming point release. But for now if HDMI audio support is important to you on an AMD system and are relying on PipeWire/PulseAudio, you may want to avoid upgrading yet to Linux 6.1.