Re: [Freedreno] [PATCH 2/3] drm/msm/dpu1: Add MSM8998 to hw catalog

Hi,

On Tue, 7 Sept 2021 at 22:13, Jeffrey Hugo [off-list ref] wrote:

On Wed, Sep 1, 2021 at 12:11 PM AngeloGioacchino Del Regno
[off-list ref] wrote:

quoted

Bringup functionality for MSM8998 in the DPU, driver which is mostly
the same as SDM845 (just a few variations).

Signed-off-by: AngeloGioacchino Del Regno <redacted>

I don't seem to see a cover letter for this series.

Eh, there are a fair number of differences between the MDSS versions
for 8998 and 845.

Probably a bigger question, why extend the DPU driver for 8998, when
the MDP5 driver already supports it[1]?  The MDP/DPU split is pretty
dumb, but I don't see a valid reason for both drivers supporting the
same target/display revision.  IMO, if you want this support in DPU,
remove it from MDP5.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.14&id=d6c7b2284b14c66a268a448a7a8d54f585d38785

I don't think that we should enforce such requirements. Having support
both in MDP5 and DPU would allow one to compare those two drivers,
performance, features, etc.
It might be that all MDP5-supported hardware would be also supported
by DPU, thus allowing us to remove the former driver. But until that
time I'd suggest leaving support in place.

-- 
With best wishes
Dmitry