Re: [PATCH v2 0/9] media: camss: add SM8750 support

[Qianhui Xu]

Hello Hangxiang,

thank you for the pointer, and sorry about the attribution. You are right on
the substance, so let me be precise about what happened rather than vague.

I went through all nine patches of v2 and compared them line by line against
your SM8750 v6 series and against your Kaanapali v22 series. Three of them
carry your code:

  - 1/9 qcom,sm8750-camss.yaml - 76% of the added lines are from your v6 2/7.
  - 4/9 camss-csid-980.c      - 92% of the file is your v6 5/7, 20 hunks changed.
  - 8/9 camss-vfe-gen4.c      - 84% of the file is your v22 9/14
                                (camss-vfe-1080.c), retargeted to the 980 bus
                                base, plus the SM8750 csiphy/csid/vfe tables.

The other six are our own work: the CSIPHY 2.4.0 lane table comes from
disassembly of the vendor camera.ko, and the csid error-path unwind, the CSID
frame-start reporting, the two camss-video fixes and the sm8750 DTS are new
code. I am not claiming anything there was derived from yours.

For v3 the trailers will be, for those three patches:

  From: Hangxiang Ma <hangxiang.ma@xxxxxxxxxxxxxxxx>
  Co-developed-by: Qianhui Xu <xiaqinghuan@xxxxxxxxxxxxxxxx>
  Signed-off-by: Hangxiang Ma <hangxiang.ma@xxxxxxxxxxxxxxxx>
  Signed-off-by: Qianhui Xu <xiaqinghuan@xxxxxxxxxxxxxxxx>

with Atiya's Co-developed-by/Signed-off-by kept in the csid-980 one, since it
is already in your v6 5/7, and a short note under the --- line naming the
series it is based on and listing what we changed. 8/9 will point at the
Kaanapali v22 series, not at the SM8750 one - that was the part of my earlier
description that was simply wrong.

On posting: I will hold the SM8750 series. Nothing further will be sent until
your team has rebased onto Kaanapali, and when we do send it will be rebased on
top of your trees with the trailers above.

On splitting: I would rather not split the SM8750 generation support out,
because the binding, the CSID 980, the VFE gen4 and the DTS only make sense
together and would be reviewed twice. What can be separated cleanly are three
patches that do not touch your code at all and are not SM8750 specific:

  - media: camss: csid: unwind the power-on path through a single error label
  - media: camss: video: check that a buffer is DMA contiguous
  - media: camss: video: stop the subdevices already started when a start fails

Those are pure camss framework cleanups against the pristine tree. If you would
rather not see them before your rebase, say so and I will keep them back too -
otherwise I would send them as a small standalone series so they do not sit
behind the SM8750 work. No dates from me on either; I would rather wait than
add review load at the wrong moment.

One thing worth flagging separately: Vladimir has asked for the CSIPHY to move
to drivers/phy/qualcomm/phy-qcom-mipi-csi2-core.c, following the SM8450 series.
That affects 2/9 only and is independent of your series, but it means the
CSIPHY part will change shape before any repost.

Thanks for the review and for the patience.

Best regards,
Qianhui