[PATCH v2 1/3] drm/msm/dsi: Use existing per-interface slice count in DSC timing

[Dmitry Baryshkov]

On Sun, Feb 09, 2025 at 10:42:52PM +0100, Marijn Suijten wrote:
> When configuring the timing of DSI hosts (interfaces) in
> dsi_timing_setup() all values written to registers are taking
> bonded-mode into account by dividing the original mode width by 2
> (half the data is sent over each of the two DSI hosts), but the full
> width instead of the interface width is passed as hdisplay parameter to
> dsi_update_dsc_timing().
> 
> Currently only msm_dsc_get_slices_per_intf() is called within
> dsi_update_dsc_timing() with the `hdisplay` argument which clearly
> documents that it wants the width of a single interface (which, again,
> in bonded DSI mode is half the total width of the mode) resulting in all
> subsequent values to be completely off.
> 
> However, as soon as we start to pass the halved hdisplay
> into dsi_update_dsc_timing() we might as well discard
> msm_dsc_get_slices_per_intf() since the value it calculates is already
> available in dsc->slice_count which is per-interface by the current
> design of MSM DPU/DSI implementations and their use of the DRM DSC
> helpers.
> 
> Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
> Signed-off-by: Marijn Suijten <marijn.suijten at somainline.org>
> ---
>  drivers/gpu/drm/msm/dsi/dsi_host.c   |  8 ++++----
>  drivers/gpu/drm/msm/msm_dsc_helper.h | 11 -----------
>  2 files changed, 4 insertions(+), 15 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>

-- 
With best wishes
Dmitry