[brkosebay]

Part 19 of 23 of the iPad 5 (J71t) series in this repository; merge after #111.

Problem

The codec's playback mixer source selectors kept whatever value they had, which left a silent or duplicated channel after a codec reset or firmware use.

Change

Assign mixer buses 0 and 1 to ASP RX slots 0 and 1 before enabling playback, as iOS does.

Testing

• Hardware: iPad 5 Wi-Fi (J71t). Hands-on testing on 2026-11-11 with an integrated build of this series, made before the final failure-path fixes, covered the speakers.
• Not covered on hardware: headphones. Headphone jack detection is not part of this series: wired headphones are selected by hand with the codec's Output Select control.
• 2026-11-12: no further hardware test of this change beyond the above. The top of this series applies to the same kernel tree as the release build tested on J71t that day (20+ warm restarts without a freeze).
• Host: the Linux test suite passes at this branch's head, and the kernel and m1n1 patch series apply on apple-16k and apple-4k. At the top of the series the applied kernel tree is identical to the one in the built release image.
• Other boards that share these drivers or compatibles have not been tested.

Dependencies

Depends on #111.

This branch is stacked on the PRs it depends on and carries their commits; the change of this PR is its last commit, "ASoC: cs42l81: Initialize the stereo playback mixer sources".

🤖 Generated with Claude Code

[henrikklee]

Landing this as your commit, unchanged, with J71t speakers marked working in the device data. The branch now holds only this topic on top of main; your previous head (the whole stack up to here) is kept as tag contrib/brkosebay-j71t-audio. Please check the speakers still play in stereo on the next nightly.