On Fri, Jan 05, 2024 at 11:19:23AM +0900, Hidenori Kobayashi wrote:
> On Thu, Jan 04, 2024 at 01:04:27PM +0300, Dan Carpenter wrote:
> > On Thu, Dec 28, 2023 at 06:39:25PM +0900, Hidenori Kobayashi wrote:
> > > The pad's flags is checked in media_entity_pads_init(), so it has to be
> > > initialized beforehand. The ops initialization is also moved together
> > > for readability.
> > >
> >
> > How does this bug look like to a user? What is the Fixes tag? Does
> > this need to be backported to stable?
>
> I suppose I should have included those in the commit message.
>
> 1) To a user, the imgu driver fails to probe with the following message:
>
> [ 14.596315] ipu3-imgu 0000:00:05.0: failed initialize subdev media entity (-22)
> [ 14.596322] ipu3-imgu 0000:00:05.0: failed to register subdev0 ret (-22)
> [ 14.596327] ipu3-imgu 0000:00:05.0: failed to register pipes (-22)
> [ 14.596331] ipu3-imgu 0000:00:05.0: failed to create V4L2 devices (-22)
>
Yeah. This is super useful information.
> 2) Re Fixes tag, I see that the first commit of imgu driver already
> initializes the flags after media_entity_pads_init(). The documentation
> of this API ( "Drivers must set the direction of every pad ... before
> calling media_entity_pads_init") predates the first commit. So, I guess
>
> Fixes: a0ca1627b450 ("media: staging/intel-ipu3: Add v4l2 driver based on media framework")
>
> 3) Re stable, I was not sure. The probe failure only appears after a
> check was added by Commit deb866f9e3a45ae058b21765feeffae6aea6a193. That
> check is not in linux-6.6.y branch. So I was not sure if this counts as
> "a real bug that bothers people" mentioned in the document.
Hm... I don't know either. Wait for a day and see if anyone else has
an opinion then listen to your gut and resend with whatever your gut
says?
regards,
dan carpenter
