[PATCH 2/7] drm/msm/dsi: Pass bonded-DSI hdisplay/2 to DSC timing configuration

[Dmitry Baryshkov]

On Wed, 17 Apr 2024 at 02:57, Marijn Suijten
<marijn.suijten at somainline.org> wrote:
>
> When configuring the timing of DSI hosts (interfaces) in
> dsi_timing_setup() all values written to registers are taking bonded
> DSI 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).  Thus pass the
> bonded-mode-adjusted hdisplay parameter into dsi_update_dsc_timing()
> otherwise all values written to registers by this function (i.e. the
> number of slices per interface or packet, and derived from this the EOL
> byte number) are twice too large.
>
> Inversely the panel driver is expected to only set the slice width and
> number of slices for half the panel, i.e. what will be sent by each
> host individually, rather than fixing that up like hdisplay here.
>
> 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 | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

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


-- 
With best wishes
Dmitry