On Fri, 20 Jan 2023, Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx> wrote:
> For MST the bpc is hardcoded to 8, and pipe bpp to 24.
> So avoid forcing DSC bpc for MST case.
It's likely better to warn and ignore the debug flag than to bail out.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 11 +++++------
> drivers/gpu/drm/i915/display/intel_dp_mst.c | 8 ++++++++
> 2 files changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 93aebd3683a4..3d828ea0894d 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1500,14 +1500,13 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
> if (!intel_dp_supports_dsc(intel_dp, pipe_config))
> return -EINVAL;
>
> - if (compute_pipe_bpp)
> + if (intel_dp->force_dsc_bpc && compute_pipe_bpp) {
> + pipe_bpp = intel_dp->force_dsc_bpc * 3;
> + drm_dbg_kms(&dev_priv->drm, "Input DSC BPP forced to %d\n", pipe_bpp);
> + } else if (compute_pipe_bpp) {
> pipe_bpp = intel_dp_dsc_compute_bpp(intel_dp, conn_state->max_requested_bpc);
> - else
> + } else {
> pipe_bpp = pipe_config->pipe_bpp;
> -
> - if (intel_dp->force_dsc_bpc) {
> - pipe_bpp = intel_dp->force_dsc_bpc * 3;
> - drm_dbg_kms(&dev_priv->drm, "Input DSC BPP forced to %d", pipe_bpp);
> }
>
> /* Min Input BPC for ICL+ is 8 */
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 8b0e4defa3f1..9be04c60cced 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -325,6 +325,14 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
> /* enable compression if the mode doesn't fit available BW */
> drm_dbg_kms(&dev_priv->drm, "Force DSC en = %d\n", intel_dp->force_dsc_en);
> if (ret || intel_dp->force_dsc_en) {
> + if (intel_dp->force_dsc_bpc) {
> + /*
> + * FIXME: As bpc is hardcoed to 8 bpc as mentioned above,
> + * Avoid force BPC for now.
> + */
> + drm_dbg_kms(&dev_priv->drm, "Cannot Force BPC for MST\n");
> + return -EINVAL;
> + }
> /*
> * Try to get at least some timeslots and then see, if
> * we can fit there with DSC.
--
Jani Nikula, Intel Open Source Graphics Center
