> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Ankit
> Nautiyal
> Sent: Tuesday, November 7, 2023 9:48 AM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Nikula, Jani <jani.nikula@xxxxxxxxx>
> Subject: [PATCH 4/4] drm/i915/dp: Ignore max_requested_bpc if its
> too low for DSC
>
> At the moment, while choosing the input bpc for DSC, we take into account the
> max_requested_bpc property. This creates a problem, if the
> max_requested_bpc is lower than the minimum bpc required by source with
> DSC.
>
> So consider max_requested_bpc if its within the limits that we can support with
> DSC.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 22 ++++++++++++++++++----
> 1 file changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index abc718f1a878..ea4c42a5705e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1578,6 +1578,16 @@ u8 intel_dp_dsc_max_src_input_bpc(struct
> drm_i915_private *i915)
> return 12;
> }
>
> +static int
> +intel_dp_dsc_limit_max_bpc(int max_requested_bpc, int src_dsc_max_bpc,
> +int src_dsc_min_bpc) {
> + /* Consider max_requested_bpc only if src can support it with DSC */
> + if (max_requested_bpc >= src_dsc_min_bpc)
> + return min(src_dsc_max_bpc, max_requested_bpc);
> +
> + return src_dsc_max_bpc;
> +}
> +
> int intel_dp_dsc_compute_max_bpp(const struct intel_connector *connector,
> u8 max_req_bpc)
> {
> @@ -1591,7 +1601,8 @@ int intel_dp_dsc_compute_max_bpp(const struct
> intel_connector *connector,
> if (!dsc_max_bpc)
> return dsc_max_bpc;
>
> - dsc_max_bpc = min_t(u8, dsc_max_bpc, max_req_bpc);
> + dsc_max_bpc = intel_dp_dsc_limit_max_bpc(max_req_bpc,
> dsc_max_bpc,
> +
> intel_dp_dsc_min_src_input_bpc(i915));
>
> num_bpc = drm_dp_dsc_sink_supported_input_bpcs(connector-
> >dp.dsc_dpcd,
> dsc_bpc);
> @@ -1959,8 +1970,11 @@ bool is_dsc_pipe_bpp_sufficient(struct
> drm_i915_private *i915, {
> u8 dsc_max_bpc, dsc_min_bpc, dsc_max_pipe_bpp,
> dsc_min_pipe_bpp;
>
> - dsc_max_bpc = min(intel_dp_dsc_max_src_input_bpc(i915),
> conn_state->max_requested_bpc);
> dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(i915);
> + dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(i915);
Seems like this change could have been a part of the previous patch.
Regards,
Suraj Kandpal
> +
> + dsc_max_bpc = intel_dp_dsc_limit_max_bpc(conn_state-
> >max_requested_bpc,
> + dsc_max_bpc, dsc_min_bpc);
>
> dsc_max_pipe_bpp = min(dsc_max_bpc * 3, limits->pipe.max_bpp);
> dsc_min_pipe_bpp = max(dsc_min_bpc * 3, limits->pipe.min_bpp);
> @@ -2020,14 +2034,14 @@ static int intel_dp_dsc_compute_pipe_bpp(struct
> intel_dp *intel_dp,
> }
> }
>
> + dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(i915);
> dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(i915);
> if (!dsc_max_bpc)
> return -EINVAL;
>
> - dsc_max_bpc = min_t(u8, dsc_max_bpc, max_req_bpc);
> + dsc_max_bpc = intel_dp_dsc_limit_max_bpc(max_req_bpc,
> dsc_max_bpc,
> +dsc_min_bpc);
> dsc_max_bpp = min(dsc_max_bpc * 3, limits->pipe.max_bpp);
>
> - dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(i915);
> dsc_min_bpp = max(dsc_min_bpc * 3, limits->pipe.min_bpp);
>
> /*
> --
> 2.40.1
