ASoC: cs35l56: Skip first init_completion wait in dsp_work if init_done

At the start of dsp_work() only wait for init_completion if !init_done.
This allows system suspend to re-queue dsp_work() without having to
do a dummy complete() of init_completion.

A dummy completion in system suspend would have to be conditional on
init_done. But that would create a possible race condition between our
system resume and cs35l56_init() in the corner case that we suspend right
after the SoundWire core has enumerated and reported ATTACHED.

It is safer and simpler to have cs35l56_init() as the only place that
init_completion is completed, and dsp_work() as the only place that
it is consumed.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230411152528.329803-4-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index 71565e0fccd8f733c6b672ffb56ac9f6f6f631dc..14cdbf5fd523c45e7306325804f2e6a67bd4c2ff 100644 (file)
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -866,7 +866,8 @@ static void cs35l56_dsp_work(struct work_struct *work)
        unsigned int val;
        int ret = 0;
 
-       if (!wait_for_completion_timeout(&cs35l56->init_completion,
+       if (!cs35l56->init_done &&
+           !wait_for_completion_timeout(&cs35l56->init_completion,
                                         msecs_to_jiffies(5000))) {
                dev_err(cs35l56->dev, "%s: init_completion timed out\n", __func__);
                goto complete;