[media] V4L2: mt9t031: don't Oops if asynchronous probing is attempted

The mt9t031 driver hasn't yet been updated to support asynchronous
subdevice probing. If such a probing is attempted, the driver is allowed
to fail, but it shouldn't Oops. This patch fixes such a potential NULL
pointer dereference.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/media/i2c/soc_camera/mt9t031.c b/drivers/media/i2c/soc_camera/mt9t031.c
index 47d18d0bafe7..ee7bb0ffcecb 100644
--- a/drivers/media/i2c/soc_camera/mt9t031.c
+++ b/drivers/media/i2c/soc_camera/mt9t031.c
@@ -594,9 +594,12 @@ static int mt9t031_s_power(struct v4l2_subdev *sd, int on)
                 ret = soc_camera_power_on(&client->dev, ssdd, mt9t031->clk);
                 if (ret < 0)
                         return ret;
-                vdev->dev.type = &mt9t031_dev_type;
+                if (vdev)
+                        /* Not needed during probing, when vdev isn't available yet */
+                        vdev->dev.type = &mt9t031_dev_type;
         } else {
-                vdev->dev.type = NULL;
+                if (vdev)
+                        vdev->dev.type = NULL;
                 soc_camera_power_off(&client->dev, ssdd, mt9t031->clk);
         }