[PATCH v2 17/17] soundwire: cadence: clear FIFO to avoid pop noise issue on playback start

From: Pierre-Louis Bossart
Date: Tue Mar 17 2020 - 12:34:52 EST


From: randerwang <rander.wang@xxxxxxxxxxxxxxx>

Driver should clear FIFO in PDI, or the previously stored sample data
in FIFO will generate pop noise when stream is started. The soft reset
bit will clear all the FIFO to zero and is self-cleared after that.

Signed-off-by: randerwang <rander.wang@xxxxxxxxxxxxxxx>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
drivers/soundwire/cadence_master.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index eedc4cefdab0..ecd357d1c63d 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -1503,6 +1503,7 @@ void sdw_cdns_config_stream(struct sdw_cdns *cdns,
cdns_updatel(cdns, offset, CDNS_PORTCTRL_DIRN, val);

val = pdi->num;
+ val |= CDNS_PDI_CONFIG_SOFT_RESET;
val |= ((1 << ch) - 1) << SDW_REG_SHIFT(CDNS_PDI_CONFIG_CHANNEL);
cdns_writel(cdns, CDNS_PDI_CONFIG(pdi->num), val);
}
--
2.20.1