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

Dan Carpenter dan.carpenter at oracle.com
Tue Jan 9 10:37:00 CET 2018


"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 at 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) {


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