diff mbox series

[STABLE-4.13,media] imx-media-of: avoid uninitialized variable warning

Message ID 20171004133507.3539072-1-arnd@arndb.de
State New
Headers show
Series [STABLE-4.13,media] imx-media-of: avoid uninitialized variable warning | expand

Commit Message

Arnd Bergmann Oct. 4, 2017, 1:34 p.m. UTC 
Replaces upstream commit 0b2e9e7947e7 ("media: staging/imx: remove
confusing IS_ERR_OR_NULL usage")

We get a harmless warning about a potential uninitialized variable
use in the driver:

drivers/staging/media/imx/imx-media-of.c: In function 'of_parse_subdev':
drivers/staging/media/imx/imx-media-of.c:216:4: warning: 'remote_np' may be used uninitialized in this function [-Wmaybe-uninitialized]

I reworked that code to be easier to understand by gcc in mainline,
but that commit is too large to backport. This is a much simpler
workaround, avoiding the warning by adding a fake initialization
to the variable. The driver was only introduced in linux-4.13,
so the workaround is not needed for earlier stable kernels.

Fixes: e130291212df ("[media] media: Add i.MX media core driver")
Cc: stable@vger.kernel.org
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Steve Longerbeam <steve_longerbeam@mentor.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 drivers/staging/media/imx/imx-media-of.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.9.0

Comments

Dan Carpenter Oct. 5, 2017, 12:32 p.m. UTC | #1 
On Wed, Oct 04, 2017 at 03:34:55PM +0200, Arnd Bergmann wrote:
> Replaces upstream commit 0b2e9e7947e7 ("media: staging/imx: remove

> confusing IS_ERR_OR_NULL usage")

> 

> We get a harmless warning about a potential uninitialized variable

> use in the driver:

> 

> drivers/staging/media/imx/imx-media-of.c: In function 'of_parse_subdev':

> drivers/staging/media/imx/imx-media-of.c:216:4: warning: 'remote_np' may be used uninitialized in this function [-Wmaybe-uninitialized]

> 

> I reworked that code to be easier to understand by gcc in mainline,

> but that commit is too large to backport. This is a much simpler

> workaround, avoiding the warning by adding a fake initialization

> to the variable. The driver was only introduced in linux-4.13,

> so the workaround is not needed for earlier stable kernels.

> 

> Fixes: e130291212df ("[media] media: Add i.MX media core driver")


I normally leave off the Fixes tag when it's not a bugfix.  The warning
is, as you mentioned, harmless.

regards,
dan carpenter
diff mbox series

Patch

diff --git a/drivers/staging/media/imx/imx-media-of.c b/drivers/staging/media/imx/imx-media-of.c
index b026fe66467c..90e7e702a411 100644
--- a/drivers/staging/media/imx/imx-media-of.c
+++ b/drivers/staging/media/imx/imx-media-of.c
@@ -167,7 +167,7 @@  of_parse_subdev(struct imx_media_dev *imxmd, struct device_node *sd_np,
 		of_parse_sensor(imxmd, imxsd, sd_np);
 
 	for (i = 0; i < num_pads; i++) {
-		struct device_node *epnode = NULL, *port, *remote_np;
+		struct device_node *epnode = NULL, *port, *remote_np = NULL;
 		struct imx_media_subdev *remote_imxsd;
 		struct imx_media_pad *pad;
 		int remote_pad;