Enabling DSC on ICL MST outputs is broken leading to FIFO pipe / transcoder underruns and blank screen. On TGL+ platforms MST/DSC works - after fixing the known issues in [1] - however to make this work on ICL requires more work. So far DSC on MST probably didn't get enabled for users - due to an issue fixed by [2] - but after fixing that, DSC could get enabled, leading to a blank screen in ICL/MST configurations which do work atm. To prevent this disable MST/DSC on ICL for now. [1] https://lore.kernel.org/all/20231030155843.2251023-1-imre.deak@xxxxxxxxx [2] https://lore.kernel.org/all/20231030155843.2251023-31-imre.deak@xxxxxxxxx Cc: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_dp_mst.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 82f425ef15953..60fe10f80fe45 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -43,6 +43,7 @@ #include "intel_dpio_phy.h" #include "intel_hdcp.h" #include "intel_hotplug.h" +#include "intel_vdsc.h" #include "skl_scaler.h" static int intel_dp_mst_check_constraints(struct drm_i915_private *i915, int bpp, @@ -297,6 +298,18 @@ static int intel_dp_mst_update_slots(struct intel_encoder *encoder, return 0; } +static bool +intel_dp_mst_dsc_source_support(const struct intel_crtc_state *crtc_state) +{ + struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev); + + /* + * FIXME: Enabling DSC on ICL results in blank screen and FIFO pipe / + * transcoder underruns, re-enable DSC after fixing this issue. + */ + return DISPLAY_VER(i915) >= 12 && intel_dsc_source_support(crtc_state); +} + static bool intel_dp_mst_compute_config_limits(struct intel_dp *intel_dp, struct intel_crtc_state *crtc_state, @@ -375,6 +388,9 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder, str_yes_no(ret), str_yes_no(intel_dp->force_dsc_en)); + if (!intel_dp_mst_dsc_source_support(pipe_config)) + return -EINVAL; + if (!intel_dp_mst_compute_config_limits(intel_dp, pipe_config, true, -- 2.39.2
