[PATCH] ASoC: stm32: i2s: skip useless write in slave mode

From: Olivier Moysan
Date: Tue Feb 26 2019 - 08:51:10 EST


Dummy write in capture master mode is used to gate
bus clocks. This write is useless in slave mode
as the clocks are not managed by slave.

Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
sound/soc/stm/stm32_i2s.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/stm/stm32_i2s.c b/sound/soc/stm/stm32_i2s.c
index 42ce87a35104..47c334de6b09 100644
--- a/sound/soc/stm/stm32_i2s.c
+++ b/sound/soc/stm/stm32_i2s.c
@@ -623,8 +623,8 @@ static int stm32_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
} else {
ier = I2S_IER_OVRIE;

- if (i2s->refcount == 1)
- /* dummy write to trigger capture */
+ if (STM32_I2S_IS_MASTER(i2s) && i2s->refcount == 1)
+ /* dummy write to gate bus clocks */
regmap_write(i2s->regmap,
STM32_I2S_TXDR_REG, 0);
}
--
2.20.1