[RESEND PATCH v2 2/9] soundwire: bus: use sdw_write_no_pm when setting the bus scale registers

From: Bard Liao
Date: Fri Jan 22 2021 - 02:09:45 EST


From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

When a Slave device is resumed, it may resume the bus and restart the
enumeration. During that process, we absolutely don't want to call
regular read/write routines which will wait for the resume to
complete, otherwise a deadlock occurs.

This patch fixes the same problem as the previous one, but is split to
make the life of linux-stable maintainers less painful.

Fixes: 29d158f90690 ('soundwire: bus: initialize bus clock base and scale registers')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Rander Wang <rander.wang@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
drivers/soundwire/bus.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 60c42508c6c6..b1830032b052 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -1222,7 +1222,7 @@ static int sdw_slave_set_frequency(struct sdw_slave *slave)
}
scale_index++;

- ret = sdw_write(slave, SDW_SCP_BUS_CLOCK_BASE, base);
+ ret = sdw_write_no_pm(slave, SDW_SCP_BUS_CLOCK_BASE, base);
if (ret < 0) {
dev_err(&slave->dev,
"SDW_SCP_BUS_CLOCK_BASE write failed:%d\n", ret);
@@ -1230,13 +1230,13 @@ static int sdw_slave_set_frequency(struct sdw_slave *slave)
}

/* initialize scale for both banks */
- ret = sdw_write(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
+ ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
if (ret < 0) {
dev_err(&slave->dev,
"SDW_SCP_BUSCLOCK_SCALE_B0 write failed:%d\n", ret);
return ret;
}
- ret = sdw_write(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
+ ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
if (ret < 0)
dev_err(&slave->dev,
"SDW_SCP_BUSCLOCK_SCALE_B1 write failed:%d\n", ret);
--
2.17.1