From: Hans Verkuil <hverkuil@xs4all.nl>
Date: Thu, 25 Jul 2019 12:48:21 +0000 (-0400)
Subject: media: v4l2-dev: fix WARN_ON(!vdev->device_caps)
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=049e684f2de9daa31a32423e16d2d3bd6bbd286f;p=linux.git

media: v4l2-dev: fix WARN_ON(!vdev->device_caps)

Device nodes of type VFL_TYPE_SUBDEV have a 0 device_caps, so they
trigger this warning. Add a check against VFL_TYPE_SUBDEV.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Fixes: 3c1350501c21 ("media: v4l2-dev/ioctl: require non-zero device_caps, verify sane querycap results")
Reported-by: Jan Kotas <jank@cadence.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---

diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index 3af72e3bbd65b..a1c61d6f3b9b0 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -859,8 +859,8 @@ int __video_register_device(struct video_device *vdev,
 	/* the v4l2_dev pointer MUST be present */
 	if (WARN_ON(!vdev->v4l2_dev))
 		return -EINVAL;
-	/* the device_caps field MUST be set */
-	if (WARN_ON(!vdev->device_caps))
+	/* the device_caps field MUST be set for all but subdevs */
+	if (WARN_ON(type != VFL_TYPE_SUBDEV && !vdev->device_caps))
 		return -EINVAL;
 
 	/* v4l2_fh support */