The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From fe26ae6ac8b88fcdac5036b557c129a17fe520d2 Mon Sep 17 00:00:00 2001 From: Imre Deak <[email protected]> Date: Mon, 9 Feb 2026 15:38:16 +0200 Subject: [PATCH] drm/i915/dp: Fix pipe BPP clamping due to HDR The pipe BPP value shouldn't be set outside of the source's / sink's valid pipe BPP range, ensure this when increasing the minimum pipe BPP value to 30 due to HDR. While at it debug print if the HDR mode was requested for a connector by setting the corresponding HDR connector property. This indicates if the requested HDR mode could not be enabled, since the selected pipe BPP is below 30, due to a sink capability or link BW limit. v2: - Also handle the case where the sink could support the target 30 BPP only in DSC mode due to a BW limit, but the sink doesn't support DSC or 30 BPP as a DSC input BPP. (Chaitanya) - Debug print the connector's HDR mode in the link config dump, to indicate if a BPP >= 30 required by HDR couldn't be reached. (Ankit) - Add Closes: trailer. (Ankit) - Don't print the 30 BPP-outside of valid BPP range debug message if the min BPP is already > 30 (and so a target BPP >= 30 required for HDR is ensured). Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/7052 Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15503 Fixes: ba49a4643cf53 ("drm/i915/dp: Set min_bpp limit to 30 in HDR mode") Cc: Chaitanya Kumar Borah <[email protected]> Cc: <[email protected]> # v6.18+ Reviewed-by: Ankit Nautiyal <[email protected]> # v1 Reviewed-by: Chaitanya Kumar Borah <[email protected]> Signed-off-by: Imre Deak <[email protected]> Link: https://patch.msgid.link/[email protected] (cherry picked from commit 08b7ef16b6a03e8c966e286ee1ac608a6ffb3d4a) Signed-off-by: Joonas Lahtinen <[email protected]> --- drivers/gpu/drm/i915/display/intel_dp.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 7e022c47e8ac2..e9f1ee1eafae7 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2665,6 +2665,7 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp, bool dsc, struct link_config_limits *limits) { + struct intel_display *display = to_intel_display(intel_dp); bool is_mst = intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST); struct intel_connector *connector = to_intel_connector(conn_state->connector); @@ -2677,8 +2678,7 @@ 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_in_hdr_mode(conn_state) ? 30 : - intel_dp_min_bpp(crtc_state->output_format); + limits->pipe.min_bpp = intel_dp_min_bpp(crtc_state->output_format); if (is_mst) { /* * FIXME: If all the streams can't fit into the link with their @@ -2694,6 +2694,19 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp, respect_downstream_limits); } + if (!dsc && intel_dp_in_hdr_mode(conn_state)) { + if (intel_dp_supports_dsc(intel_dp, connector, crtc_state) && + limits->pipe.max_bpp >= 30) + limits->pipe.min_bpp = max(limits->pipe.min_bpp, 30); + else + drm_dbg_kms(display->drm, + "[CONNECTOR:%d:%s] Can't force 30 bpp for HDR (pipe bpp: %d-%d DSC-support: %s)\n", + connector->base.base.id, connector->base.name, + limits->pipe.min_bpp, limits->pipe.max_bpp, + str_yes_no(intel_dp_supports_dsc(intel_dp, connector, + crtc_state))); + } + if (dsc && !intel_dp_dsc_compute_pipe_bpp_limits(connector, limits)) return false; @@ -2825,10 +2838,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, } drm_dbg_kms(display->drm, - "DP lane count %d clock %d bpp input %d compressed " FXP_Q4_FMT " link rate required %d available %d\n", + "DP lane count %d clock %d bpp input %d compressed " FXP_Q4_FMT " HDR %s link rate required %d available %d\n", pipe_config->lane_count, pipe_config->port_clock, pipe_config->pipe_bpp, FXP_Q4_ARGS(pipe_config->dsc.compressed_bpp_x16), + str_yes_no(intel_dp_in_hdr_mode(conn_state)), intel_dp_config_required_rate(pipe_config), intel_dp_max_link_data_rate(intel_dp, pipe_config->port_clock, -- 2.51.0
