[PATCH 5.11 509/775] soundwire: bus: use sdw_update_no_pm when initializing a device

From: Greg Kroah-Hartman
Date: Tue Mar 02 2021 - 00:12:37 EST


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

[ Upstream commit b04c975e654cfdea6d691cd403b5a81cce7e593d ]

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.

Fixes: 60ee9be25571 ('soundwire: bus: add PM/no-PM versions of read/write functions')
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>
Link: https://lore.kernel.org/r/20210122070634.12825-2-yung-chuan.liao@xxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/soundwire/bus.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index d1e8c3a54976b..60c42508c6c6b 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -489,6 +489,18 @@ sdw_read_no_pm(struct sdw_slave *slave, u32 addr)
return buf;
}

+static int sdw_update_no_pm(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
+{
+ int tmp;
+
+ tmp = sdw_read_no_pm(slave, addr);
+ if (tmp < 0)
+ return tmp;
+
+ tmp = (tmp & ~mask) | val;
+ return sdw_write_no_pm(slave, addr, tmp);
+}
+
/**
* sdw_nread() - Read "n" contiguous SDW Slave registers
* @slave: SDW Slave
@@ -1256,7 +1268,7 @@ static int sdw_initialize_slave(struct sdw_slave *slave)
val = slave->prop.scp_int1_mask;

/* Enable SCP interrupts */
- ret = sdw_update(slave, SDW_SCP_INTMASK1, val, val);
+ ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, val, val);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INTMASK1 write failed:%d\n", ret);
@@ -1271,7 +1283,7 @@ static int sdw_initialize_slave(struct sdw_slave *slave)
val = prop->dp0_prop->imp_def_interrupts;
val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;

- ret = sdw_update(slave, SDW_DP0_INTMASK, val, val);
+ ret = sdw_update_no_pm(slave, SDW_DP0_INTMASK, val, val);
if (ret < 0)
dev_err(slave->bus->dev,
"SDW_DP0_INTMASK read failed:%d\n", ret);
--
2.27.0