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From:   Vinod Koul <vinod.koul@intel.com>
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>,
        Sanyog Kale <sanyog.r.kale@intel.com>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Vinod Koul <vinod.koul@intel.com>
Subject: [PATCH] soundwire: Fix a signedness bug
Date:   Sun, 21 Jan 2018 10:26:31 +0530
Message-Id: <1516510591-31515-1-git-send-email-vinod.koul@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Dan Carpenter <dan.carpenter@oracle.com>

"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>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---
 drivers/soundwire/bus.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 5d7226c251e6..d6dc8e7a8614 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -771,7 +771,7 @@ 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);
+	buf = ret = sdw_read(slave, SDW_SCP_INT1);
 	if (ret < 0) {
 		dev_err(slave->bus->dev,
 					"SDW_SCP_INT1 read failed:%d", ret);
@@ -870,7 +870,7 @@ 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);
+		_buf = ret = sdw_read(slave, SDW_SCP_INT1);
 		if (ret < 0) {
 			dev_err(slave->bus->dev,
 					"SDW_SCP_INT1 read failed:%d", ret);
-- 
2.7.4