Re: [PATCH v3] drm/i915/audio: treat UHBR SST like MST for cpu_transcoder signalling
Jani Nikula <[email protected]> Tue, 28 Jul 2026 12:00:48 +0300
| Newsgroups | org.freedesktop.lists.intel-gfx,org.freedesktop.lists.intel-xe |
|---|---|
| Organization | Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland |
| Message-ID | <[email protected]> |
On Tue, 28 Jul 2026, Jani Nikula <[email protected]> wrote: > On Wed, 08 Jul 2026, Mitul Golani <[email protected]> wrote: >> Both DP MST and UHBR SST require the audio component to use a real >> cpu_transcoder (>= 0) value to identify the audio stream on a port. >> For DP MST this was already handled; for UHBR SST it was not, causing >> pin_eld_notify() to signal cpu_transcoder = -1 (the legacy SST sentinel) >> and find_audio_state() to skip the per-transcoder entry for the UHBR >> stream. >> >> After suspend/resume or replug, the ELD lookup fails and audio goes >> silent. Fix by detecting UHBR SST alongside DP MST when deciding >> whether a real cpu_transcoder value must be used for audio state >> addressing, in both the pin_eld_notify() signalling and the >> find_audio_state() lookup paths. > > [snip] > > Going through some merged patches while writing the pull request... Oh, and PS. Why is this not Cc: stable? BR, Jani. > >> >> - /* Non-MST */ >> + /* Legacy SST. */ > > Please be careful about tossing around "legacy". It's the bog standard > DP 1.4 non-UHBR SST that's used absolutely everywere that you're talking > about here. It's not "legacy". > > BR, > Jani. -- Jani Nikula, Intel