On Wed, Feb 12, 2025 at 03:03:47PM -0800, James A. MacInnes wrote:
> Type-C DisplayPort inoperable due to incorrect porch settings.
> - Re-used wide_bus_en as flag to prevent porch shifting
Unfortunately I don't know enough details to comment on this change.
Maybe Abhinav can check it. I can only notice that msm-4.14 disables
programmable_fetch_config for non-DSI calls. Would disabling that call
for DP interface fix your issue?
>
> Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
> Signed-off-by: James A. MacInnes <james.a.macin...@gmail.com>
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> index abd6600046cb..a21addc4794f 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> @@ -94,17 +94,21 @@ static void drm_mode_to_intf_timing_params(
> timing->vsync_polarity = 0;
> }
>
> - /* for DP/EDP, Shift timings to align it to bottom right */
> - if (phys_enc->hw_intf->cap->type == INTF_DP) {
> + timing->wide_bus_en = dpu_encoder_is_widebus_enabled(phys_enc->parent);
> + timing->compression_en = dpu_encoder_is_dsc_enabled(phys_enc->parent);
> +
> + /*
> + * For DP/EDP, Shift timings to align it to bottom right.
> + * wide_bus_en is set for everything excluding SDM845 &
> + * porch changes cause DisplayPort failure and HDMI tearing.
> + */
> + if (phys_enc->hw_intf->cap->type == INTF_DP && timing->wide_bus_en) {
> timing->h_back_porch += timing->h_front_porch;
> timing->h_front_porch = 0;
> timing->v_back_porch += timing->v_front_porch;
> timing->v_front_porch = 0;
> }
>
> - timing->wide_bus_en = dpu_encoder_is_widebus_enabled(phys_enc->parent);
> - timing->compression_en = dpu_encoder_is_dsc_enabled(phys_enc->parent);
> -
> /*
> * for DP, divide the horizonal parameters by 2 when
> * widebus is enabled
>
> --
> 2.43.0
>
--
With best wishes
Dmitry
