Hi Sakari,
On 3/2/23 21:22, Sakari Ailus wrote:
> Link validation currently accesses invalid pointers if the link passed to it
> is not between two sub-devices. This is of course a driver bug.
>
> Ignore the error but print a debug message, as this is how it used to work
> previously.
>
> Fixes: a6b995ed03ff ("media: subdev: use streams in v4l2_subdev_link_validate()")
> Reported-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> Hi Hans,
>
> Could you test this?
Yes, thank you for the fix.
I can confirm that this fixes the oops on my Surface Go 1 and
that it makes the IPU3 attached cameras work again:
Tested-by: Hans de Goede <hdegoede@xxxxxxxxxx>
or better just replace the Reported-by with:
Reported-and-tested-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Regards,
Hans
> The bug is of course in the ImgU driver and this reverts to the old
> pre-streams behaviour. It silently fails instead of oopsing. The ImgU driver
> needs to be fixed and I think we could make this return an error at the same
> time. Right now I can't be sure the ImgU driver is the only one suffering
> from this, but if so, it's likely to be broken anyway.
>
> - Sakari
>
> drivers/media/v4l2-core/v4l2-subdev.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
> index dff1d9be7841..a6c80096586e 100644
> --- a/drivers/media/v4l2-core/v4l2-subdev.c
> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
> @@ -1224,6 +1224,17 @@ int v4l2_subdev_link_validate(struct media_link *link)
> struct v4l2_subdev_state *source_state, *sink_state;
> int ret;
>
> + if (!is_media_entity_v4l2_subdev(link->sink->entity)) {
> + pr_debug("entity \"%s\" not a V4L2 sub-device, driver bug!\n",
> + link->sink->entity->name);
> + return 0;
> + }
> + if (!is_media_entity_v4l2_subdev(link->source->entity)) {
> + pr_debug("entity \"%s\" not a V4L2 sub-device, driver bug!\n",
> + link->source->entity->name);
> + return 0;
> + }
> +
> sink_sd = media_entity_to_v4l2_subdev(link->sink->entity);
> source_sd = media_entity_to_v4l2_subdev(link->source->entity);
>
