From ba49a4643cf53c6e9582b4a31142b67f5829cd82 Mon Sep 17 00:00:00 2001 From: Chaitanya Kumar Borah Date: Wed, 30 Jul 2025 11:25:23 +0530 Subject: [PATCH] drm/i915/dp: Set min_bpp limit to 30 in HDR mode Update intel_dp_compute_config_limits() to use a minimum of 30 bits per pixel when the connector is in HDR mode (specifically, when EOTF is SMPTE ST2084), aligning with HDR display requirements. To support this, the function now takes a drm_connector_state instead of an intel_connector, and the required updates are made in all call sites, including MST handling. This ensures sufficient bitdepth for HDR content to avoid banding. If the required bandwidth for 30 bpp cannot be supported, the driver will either fall back to DSC or reject the mode during atomic check if DSC is not supported. Signed-off-by: Chaitanya Kumar Borah Reviewed-by: Uma Shankar Signed-off-by: Suraj Kandpal Link: https://lore.kernel.org/r/20250730055523.2214966-3-chaitanya.kumar.borah@intel.com --- drivers/gpu/drm/i915/display/intel_dp.c | 11 +++++++---- drivers/gpu/drm/i915/display/intel_dp.h | 2 +- drivers/gpu/drm/i915/display/intel_dp_mst.c | 11 +++++++---- 3 files changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 8a155bc958f06..996edb8dededc 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2536,13 +2536,15 @@ intel_dp_dsc_compute_pipe_bpp_limits(struct intel_dp *intel_dp, bool intel_dp_compute_config_limits(struct intel_dp *intel_dp, - struct intel_connector *connector, + struct drm_connector_state *conn_state, struct intel_crtc_state *crtc_state, bool respect_downstream_limits, bool dsc, struct link_config_limits *limits) { bool is_mst = intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST); + struct intel_connector *connector = + to_intel_connector(conn_state->connector); limits->min_rate = intel_dp_min_link_rate(intel_dp); limits->max_rate = intel_dp_max_link_rate(intel_dp); @@ -2552,7 +2554,8 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp, limits->min_lane_count = intel_dp_min_lane_count(intel_dp); limits->max_lane_count = intel_dp_max_lane_count(intel_dp); - limits->pipe.min_bpp = intel_dp_min_bpp(crtc_state->output_format); + limits->pipe.min_bpp = intel_dp_in_hdr_mode(conn_state) ? 30 : + intel_dp_min_bpp(crtc_state->output_format); if (is_mst) { /* * FIXME: If all the streams can't fit into the link with their @@ -2651,7 +2654,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, joiner_needs_dsc = intel_dp_joiner_needs_dsc(display, num_joined_pipes); dsc_needed = joiner_needs_dsc || intel_dp->force_dsc_en || - !intel_dp_compute_config_limits(intel_dp, connector, pipe_config, + !intel_dp_compute_config_limits(intel_dp, conn_state, pipe_config, respect_downstream_limits, false, &limits); @@ -2685,7 +2688,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, str_yes_no(ret), str_yes_no(joiner_needs_dsc), str_yes_no(intel_dp->force_dsc_en)); - if (!intel_dp_compute_config_limits(intel_dp, connector, pipe_config, + if (!intel_dp_compute_config_limits(intel_dp, conn_state, pipe_config, respect_downstream_limits, true, &limits)) diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h index 5def589e3c0e8..f90cfd1dbbd05 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.h +++ b/drivers/gpu/drm/i915/display/intel_dp.h @@ -193,7 +193,7 @@ void intel_dp_wait_source_oui(struct intel_dp *intel_dp); int intel_dp_output_bpp(enum intel_output_format output_format, int bpp); bool intel_dp_compute_config_limits(struct intel_dp *intel_dp, - struct intel_connector *connector, + struct drm_connector_state *conn_state, struct intel_crtc_state *crtc_state, bool respect_downstream_limits, bool dsc, diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 74497c9a0554d..352f7ef29c281 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -611,12 +611,15 @@ adjust_limits_for_dsc_hblank_expansion_quirk(struct intel_dp *intel_dp, static bool mst_stream_compute_config_limits(struct intel_dp *intel_dp, - struct intel_connector *connector, + struct drm_connector_state *conn_state, struct intel_crtc_state *crtc_state, bool dsc, struct link_config_limits *limits) { - if (!intel_dp_compute_config_limits(intel_dp, connector, + struct intel_connector *connector = + to_intel_connector(conn_state->connector); + + if (!intel_dp_compute_config_limits(intel_dp, conn_state, crtc_state, false, dsc, limits)) return false; @@ -665,7 +668,7 @@ static int mst_stream_compute_config(struct intel_encoder *encoder, joiner_needs_dsc = intel_dp_joiner_needs_dsc(display, num_joined_pipes); dsc_needed = joiner_needs_dsc || intel_dp->force_dsc_en || - !mst_stream_compute_config_limits(intel_dp, connector, + !mst_stream_compute_config_limits(intel_dp, conn_state, pipe_config, false, &limits); if (!dsc_needed) { @@ -691,7 +694,7 @@ static int mst_stream_compute_config(struct intel_encoder *encoder, str_yes_no(intel_dp->force_dsc_en)); - if (!mst_stream_compute_config_limits(intel_dp, connector, + if (!mst_stream_compute_config_limits(intel_dp, conn_state, pipe_config, true, &limits)) return -EINVAL; -- 2.47.3