[PATCH v10 4/8] drm/msm: Add MSM-specific DSC helper methods

[Dmitry Baryshkov]

On 16/05/2023 01:01, Marijn Suijten wrote:
> On 2023-05-15 13:29:21, Jessica Zhang wrote:
> <snip>
>>> Const, as requested elsewhere.  But this function is not used anywhere
>>> in any of the series (because we replaced the usages with more sensible
>>> member accesses like slice_chunk_size).
>>
>> Acked.
>>
>> I would prefer to keep this helper so that we have a way to easily get
>> BPP information from the DRM DSC config in the future, but if you'd
>> prefer we add this helper then, I'm also ok with that.
> 
> The inverse helper is available ad DSC_BPP in drm_dsc_helper.c.  Perhaps
> we can move the two variants to the header and define them uniformly?
> This isn't MSM-specific it seems (i.e. the format supports fractional
> bpp but no RC parameters appear to be defined for such a format yet).

I think DSC_BPP was removed (around v2 or v3 if I read changelog correctly).

As for the fraction-point BPP, I think AMD supports .5 bpp granularity, 
see drivers/gpu/drm/amd/display/dc/dml/dsc/qp_tables.h

-- 
With best wishes
Dmitry