Re: [PATCH] ASoC: codec: pcm1681: Acquire sck when bound to a card

[Bartosz Golaszewski]

On Wed, Oct 21, 2026 at 11:12:28AM +0800, Shawn Guo wrote:
> The sck clock is taken once at i2c probe and held for the lifetime of
> the device. On Qualcomm boards it is an LPASS clock exported by the
> q6prm clock controller, which lives on the DSP and is unregistered and
> registered anew whenever the ADSP is stopped and restarted. fw_devlink
> cannot tie pcm1681 to that provider, since the provider node only gets
> a device once the DSP is up, so it falls back to the remoteproc device,
> which stays bound across a DSP restart. pcm1681 is therefore never
> unbound and keeps a clk handle to the dead provider.
> 
> After an ADSP restart the first runtime resume fails with:
> 
>   pcm1681 0-004c: Failed to enable sck: -6
> 
> and there is no playback through the DAC. Even with a fresh handle the
> DAC stays silent: the new provider registers its clocks at their
> default rate (19.2 MHz), while assigned-clock-rates (12.288 MHz) was
> only applied by the i2c core at probe time.
> 
> The sound card, however, is torn down and re-created on a DSP restart.
> Move sck handling into the component probe/remove callbacks: get the
> clock, re-apply the assigned clock rates and enable it each time the
> component is bound, and release it on removal. The i2c probe now only
> sets up supplies and the regmap, keeping the cache in cache-only mode
> until the clock is running, and the cache is synced once sck is up.
> Runtime PM is enabled and disabled together with the clock.
> 
> Fixes: 8987e9a24f45 ("ASoC: codec: pcm1681: Add optional SCK clock and runtime PM support")
> Signed-off-by: Shawn Guo <shengchao.guo@xxxxxxxxxxxxxxxx>
> ---
 
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>