ASoC: cs35l41: Fix broken shared boost activation

Enabling the active/passive shared boosts requires setting SYNC_EN, but
*not* before receiving the PLL Lock signal.

Due to improper error handling, it was not obvious that waiting for the
completion operation times out and, consequently, the shared boost is
never activated.

Further investigations revealed the signal is triggered while
snd_pcm_start() is executed, right after receiving the
SNDRV_PCM_TRIGGER_START command, which happens long after the
SND_SOC_DAPM_PRE_PMU event handler is invoked as part of
snd_pcm_prepare().  That is where cs35l41_global_enable() is called
from.

Increasing the wait duration doesn't help, as it only causes an
unnecessary delay in the invocation of snd_pcm_start().  Moving the wait
and the subsequent regmap operations to the SNDRV_PCM_TRIGGER_START
callback is not a solution either, since they would be executed in an
IRQ-off atomic context.

Solve the issue by setting the SYNC_EN bit in PWR_CTRL3 register right
after receiving the PLL Lock interrupt.

Additionally, drop the unnecessary writes to PWR_CTRL1 register, part of
the original mdsync_up_seq, which would have toggled GLOBAL_EN with
unwanted consequences on PLL locking behavior.

Fixes: f5030564938b ("ALSA: cs35l41: Add shared boost feature")
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: David Rhodes <david.rhodes@cirrus.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20230907171010.1447274-5-cristian.ciocaltea@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/sound/soc/codecs/cs35l41.h b/sound/soc/codecs/cs35l41.h
index 34d967d4372b..c85cbc1dd333 100644
--- a/sound/soc/codecs/cs35l41.h
+++ b/sound/soc/codecs/cs35l41.h
@@ -33,7 +33,6 @@ struct cs35l41_private {
 	int irq;
 	/* GPIO for /RST */
 	struct gpio_desc *reset_gpio;
-	struct completion pll_lock;
 };
 
 int cs35l41_probe(struct cs35l41_private *cs35l41, const struct cs35l41_hw_cfg *hw_cfg);