Re: [PATCH v2 5/7] drm/msm/dsi: Account for DSC's bits_per_pixel having 4 fractional bits

From: Marijn Suijten
Date: Wed Oct 05 2022 - 17:33:47 EST


On 2022-10-06 00:11:06, Dmitry Baryshkov wrote:
> On 06/10/2022 00:08, Marijn Suijten wrote:
> > [..]
> > Aside fixing that to assign these values (through the proper constants)
> > to dsc->mux_word_size, is it worth looking for the right parameters for
> > other bpc or return -EINVAL if bpc isn't 8, to uphold this comment until
> > support for other bpc is validated?
>
> I'd say, return -EINVAL or -EOPNOTSUPP for now, let's fix that later.
> It's definitely a separate change. Let's wait for a device with such
> panel to be able to test it.

According to [1] these four fields specifically are different for other
BPC; I can add a -EOPNOTSUPP and DRM_DEV_ERROR requesting a test, or
insert the values; there's only 8BPC and 10BPC, no 12BPC.

Aside that we need a different initial_offset = 5632 for other bpp/bpc
pairs.

[1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-drivers/-/blob/DISPLAY.LA.2.0.r1-08000-WAIPIO.0/msm/sde_dsc_helper.c#L110-139

- Marijn