Messages in this thread | | | Date | Wed, 26 Oct 2022 22:41:53 +0300 | Subject | Re: [PATCH v4 06/10] drm/msm/dsi: Migrate to drm_dsc_compute_rc_parameters() | From | Dmitry Baryshkov <> |
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On 26/10/2022 21:28, Marijn Suijten wrote: > As per the FIXME this code is entirely duplicate with what is already > provided inside drm_dsc_compute_rc_parameters(), supposedly because that > function was yielding "incorrect" results while in reality the panel > driver(s?) used for testing were providing incorrect parameters. > > For example, this code from downstream assumed dsc->bits_per_pixel to > contain an integer value, whereas the upstream drm_dsc_config struct > stores it with 4 fractional bits. drm_dsc_compute_rc_parameters() > already accounts for this feat while the panel driver used for testing > [1] wasn't, hence making drm_dsc_compute_rc_parameters() seem like it > was returning an incorrect result. > Other users of dsc->bits_per_pixel inside dsi_populate_dsc_params() also > treat it in the same erroneous way, and will be addressed in a separate > patch. > In the end, using drm_dsc_compute_rc_parameters() spares both a lot of > duplicate code and erratic behaviour. > > [1]: https://git.linaro.org/people/vinod.koul/kernel.git/commit/?h=topic/pixel3_5.18-rc1&id=1d7d98ad564f1ec69e7525e07418918d90f247a1 > > Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") > Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com> > Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org> > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 64 +++--------------------------- > 1 file changed, 6 insertions(+), 58 deletions(-)
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Thank you for the expanded explanation.
-- With best wishes Dmitry
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