media: stkwebcam: Bugfix for wrong return values

BugLink: https://bugs.launchpad.net/bugs/1857158
[ Upstream commit 3c28b91380dd1183347d32d87d820818031ebecf ]

usb_control_msg returns in case of a successfully sent message the number
of sent bytes as a positive number. Don't use this value as a return value
for stk_camera_read_reg, as a non-zero return value is used as an error
condition in some cases when stk_camera_read_reg is called.

Signed-off-by: Andreas Pape <ap@ca-pape.de>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c
index a7da1356a36ef57ec975b21b50a5b19588cd5c86..6992e84f8a8bb4405db9c841a2c1193b6858a983 100644 (file)
--- a/drivers/media/usb/stkwebcam/stk-webcam.c
+++ b/drivers/media/usb/stkwebcam/stk-webcam.c
@@ -164,7 +164,11 @@ int stk_camera_read_reg(struct stk_camera *dev, u16 index, u8 *value)
                *value = *buf;
 
        kfree(buf);
-       return ret;
+
+       if (ret < 0)
+               return ret;
+       else
+               return 0;
 }
 
 static int stk_start_stream(struct stk_camera *dev)