Re: [PATCH RFC v5 4/6] drm/sprd: add Unisoc's drm display controller driver

[Emil Velikov]

Hey Kevin,

On Sun, 15 Mar 2020 at 23:19, Kevin Tang <kevin3.tang@xxxxxxxxx> wrote:
>
> Adds DPU(Display Processor Unit) support for the Unisoc's display subsystem.
> It's support multi planes, scaler, rotation, PQ(Picture Quality) and more.
>
> Cc: Orson Zhai <orsonzhai@xxxxxxxxx>
> Cc: Baolin Wang <baolin.wang@xxxxxxxxxx>
> Cc: Chunyan Zhang <zhang.lyra@xxxxxxxxx>
> Signed-off-by: Kevin Tang <kevin.tang@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/sprd/Makefile       |   5 +-
>  drivers/gpu/drm/sprd/dpu/Makefile   |   7 +
>  drivers/gpu/drm/sprd/dpu/dpu_r2p0.c | 750 ++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/sprd/sprd_dpu.c     | 501 ++++++++++++++++++++++++
>  drivers/gpu/drm/sprd/sprd_dpu.h     | 170 ++++++++
>  drivers/gpu/drm/sprd/sprd_drm.c     |   1 +
>  drivers/gpu/drm/sprd/sprd_drm.h     |   2 +

Seems like v5 (patch at least, I did not look at the rest) does not
address a handful of the feedback.
 - Access registers via readl/writel, instead of current approach
 - With ^^ you can drop the compiler workaround
 - Checking for unsupported KMS properties (format, rotation, etc)
should happen in the XXX_check callbacks
 - Remove always true checks, around the (rather moot) abstraction layer

For the future, please keep the revision/changelog within the
corresponding patch. This way reviewers can see, from the onset, what
is addressed.
Look at `git log -- drivers/gpu/drm` for examples.


-Emil