4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit ee494cf377e142f65f202fadf0d859f8e12119fb ]
Currently v4l2_device_register_subdev_nodes() does not initialize the dev_parent field of the video_device structs it creates for subdevices being registered. This leads to __video_register_device() falling back to the parent device of associated v4l2_device struct, which often does not match the physical device the subdevice is registered for.
Due to the problem above, the links between real devices and v4l-subdev nodes cannot be obtained from sysfs, which might be confusing for the userspace trying to identify the hardware.
Fix this by initializing the dev_parent field of the video_device struct with the value of dev field of the v4l2_subdev struct. In case of subdevices without a parent struct device, the field will be NULL and the old behavior will be preserved by the semantics of __video_register_device().
Signed-off-by: Tomasz Figa tfiga@chromium.org Acked-by: Sakari Ailus sakari.ailus@linux.intel.com Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/media/v4l2-core/v4l2-device.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c index df0ac38c4050..e0ddb9a52bd1 100644 --- a/drivers/media/v4l2-core/v4l2-device.c +++ b/drivers/media/v4l2-core/v4l2-device.c @@ -247,6 +247,7 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
video_set_drvdata(vdev, sd); strscpy(vdev->name, sd->name, sizeof(vdev->name)); + vdev->dev_parent = sd->dev; vdev->v4l2_dev = v4l2_dev; vdev->fops = &v4l2_subdev_fops; vdev->release = v4l2_device_release_subdev_node;