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Liviu Nicoara
b2047b8cad
Commit902f497a1f("ASoC: codecs: lpass-wsa-macro: remove useless gain read/write sequence") removed the read and write of the digital volume register in wsa_macro_enable_interpolator(), on the grounds that writing back the value just read does nothing. The comment above it, "apply gain after int clk is enabled", was left in place. On the Dell XPS 13 9345 (X1E80100, four WSA8845 amplifiers on two WSA macros) the write does something: a volume change made while the path is idle does not take effect when playback starts. Lowering the digital volume from 81 to 63 with nothing playing, then playing a test tone, gave about the same level as before the change. With the rewrite restored, lowering it from 81 to 69 while idle played audibly quieter, and restoring 81 while idle brought the level back. Changes made during playback take effect with or without the rewrite. The register already holds the new value when this happens. Without the rewrite, after an idle change from 69 to 81, playback stayed at the old level while the register, read from the hardware through /dev/mem, held the new one (0xfd). Writing that same value back through /dev/mem brought the level up at once. This is the behaviour described in commit46188db080("ASoC: codecs: lpass-wsa-macro: fix compander volume hack"): "the volume registers still need to be written after enabling clocks in order for any prior updates to take effect." The value read comes from the register cache, so the write pushes the last requested volume to the hardware once its clock runs. Restore the rewrite in the interpolator's POST_PMU event only. The mix path event removed later in the same series is not brought back. Fixes:902f497a1f("ASoC: codecs: lpass-wsa-macro: remove useless gain read/write sequence") Cc: [email protected] Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Liviu Nicoara <[email protected]> Reviewed-by: Johan Hovold <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Mark Brown <[email protected]>