[media] v4l2-compat-ioctl32: VIDIOC_S_EDID should return all fields o…

…n error

Most ioctls do not have to write back the contents of the argument
if an error is returned. But VIDIOC_S_EDID is an exception together
with the EXT_CTRLS ioctls (already handled correctly).

Add this exception to v4l2-compat-ioctl32.

This fixes a compliance error when using compat32 and trying to
set a new EDID with more blocks than the hardware supports. In
that case the driver will return -E2BIG and set edid.blocks to the
actual maximum number of blocks. This field was never copied back
to userspace due to this bug.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/v4l2-core/v4l2-compat-ioctl32.c

@@ -990,6 +990,10 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 		if (put_v4l2_ext_controls32(&karg.v2ecs, up))
 			err = -EFAULT;
 		break;
+	case VIDIOC_S_EDID:
+		if (put_v4l2_edid32(&karg.v2edid, up))
+			err = -EFAULT;
+		break;
 	}
 	if (err)
 		return err;
@@ -1011,7 +1015,6 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar
 		break;
 
 	case VIDIOC_G_EDID:
-	case VIDIOC_S_EDID:
 		err = put_v4l2_edid32(&karg.v2edid, up);
 		break;