[PATCH 1/2] soundwire: Fix a signedness bug

Dan Carpenter
2018-01-09T09:37:00Z

"ret" is an int and "buf" is a u8. sdw_read() returns negative error
codes which are truncated to the u8, 0-255 range before being stored as
an int. It means that "ret" can't be less than zero.

Fixes: b0a9c37b0178 ("soundwire: Add slave status handling")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 4c345197eb55..ac88031f7664 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -771,12 +771,13 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);

/* Read Instat 1, Instat 2 and Instat 3 registers */
- ret = buf = sdw_read(slave, SDW_SCP_INT1);
+ ret = sdw_read(slave, SDW_SCP_INT1);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT1 read failed:%d", ret);
return ret;
}
+ buf = ret;

ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, buf2);
if (ret < 0) {
@@ -870,12 +871,13 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
* Read status again to ensure no new interrupts arrived
* while servicing interrupts.
*/
- ret = _buf = sdw_read(slave, SDW_SCP_INT1);
+ ret = sdw_read(slave, SDW_SCP_INT1);
if (ret < 0) {
dev_err(slave->bus->dev,
"SDW_SCP_INT1 read failed:%d", ret);
return ret;
}
+ _buf = ret;

ret = sdw_nread(slave, SDW_SCP_INTSTAT2, 2, _buf2);
if (ret < 0) {