Re: [PATCH v2 1/2] media: vimc: add ancillary lens

[Yunke Cao <yunkec@google.com>]

Hi Shuah,

Thanks for the pointers.

On Wed, Jun 22, 2022 at 12:57 AM Shuah Khan <skhan@linuxfoundation.org> wrote:
>
> On 6/19/22 7:57 PM, Yunke Cao wrote:
> > Hi Shuah,
> >
> > Thanks for the review.
> >
> > On Sat, Jun 18, 2022 at 5:01 AM Shuah Khan <skhan@linuxfoundation.org> wrote:
> >>
> >> On 6/16/22 7:57 PM, Yunke Cao wrote:
> >>> Add a basic version of vimc lens.
> >>> The lens supports V4L2_CID_FOCUS_ABSOLUTE control.
> >>> Link the lens with vimc sensors using media-controller
> >>> ancillary links.
> >>>
> >>
> >> Commit log lines are usually ~75 charracters long. Make it easier
> >> to read.
> > That's good to know. Thanks!
> > Should I send v3 and trim the commit log?
> > I'm thinking something like this:
> >
> > The lens supports FOCUS_ABSOLUTE control.
> > Link the lens with sensors using ancillary links.
> >
>
> Why is this necessary? How did you test this change? How could
> one use this feature?
>

Add lens to vimc driver and link them with sensors using ancillary links.
Provides an example of ancillary link usage.The lens supports
FOCUS_ABSOLUTE control.

Test example: With default vimc topology
> media-ctl -p
Media controller API version 5.18.0
…
- entity 28: Lens A (0 pad, 0 link)
             type V4L2 subdev subtype Lens flags 0
             device node name /dev/v4l-subdev6
- entity 29: Lens B (0 pad, 0 link)
             type V4L2 subdev subtype Lens flags 0
             device node name /dev/v4l-subdev7
>  v4l2-ctl -d /dev/v4l-subdev7 -C focus_absolute
focus_absolute: 0

Let me know what you think. Thanks!

Best,
Yunke

> >>
> >>> This change can be used to test the recently added ancillary
> >>> links.
> >>>
> >>
> >> Care to add instructions on how one would test ancillary with
> >> this feature?
> >
> > The lens shows up in the media topology. I documented it in 2/2.
> > Not sure what else is necessary here.
> >
>
> Why is this necessary? How did you test this change? How could
> one use this feature?
>
> Take a look at the some of the other commit messages e.g:
> 4a2e0a806cb58a4d3106add079488e0b56a221b6
> 5f3fb5c54d67670fa6743d2434a5bd43a97c01de
>
> This one is a good example of what would a commit log adding a
> new feature should include.
>
> commit 9b4a9b31b9aeef262b4fa211f2083c30c4391df7
> Author: Pedro Terra <pedro@terraco.de>
> Date:   Tue Aug 31 19:48:22 2021 +0200
>
>      media: vimc: Enable set resolution at the scaler src pad
>
> thanks,
> -- Shuah