diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index fe01fdf36cfd..a88b852c437c 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -45,6 +45,27 @@ #include "intel_hotplug.h" #include "skl_scaler.h" +static int intel_dp_mst_check_constraints(struct drm_i915_private *i915, int bpp, + const struct drm_display_mode *adjusted_mode, + struct intel_crtc_state *crtc_state, + bool dsc) +{ + if (intel_dp_is_uhbr(crtc_state) && DISPLAY_VER(i915) <= 13 && dsc) { + int output_bpp = bpp; + /* DisplayPort 2 128b/132b, bits per lane is always 32 */ + int symbol_clock = crtc_state->port_clock / 32; + + if (output_bpp * adjusted_mode->crtc_clock >= + symbol_clock * 72) { + drm_dbg_kms(&i915->drm, "UHBR check failed(required bw %d available %d)\n", + output_bpp * adjusted_mode->crtc_clock, symbol_clock * 72); + return -EINVAL; + } + } + + return 0; +} + static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, struct intel_crtc_state *crtc_state, int max_bpp, @@ -81,12 +102,16 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, } for (bpp = max_bpp; bpp >= min_bpp; bpp -= step) { + drm_dbg_kms(&i915->drm, "Trying bpp %d\n", bpp); + + ret = intel_dp_mst_check_constraints(i915, bpp, adjusted_mode, crtc_state, dsc); + if (ret) + continue; + crtc_state->pbn = drm_dp_calc_pbn_mode(adjusted_mode->crtc_clock, dsc ? bpp << 4 : bpp, dsc); - drm_dbg_kms(&i915->drm, "Trying bpp %d\n", bpp); - slots = drm_dp_atomic_find_time_slots(state, &intel_dp->mst_mgr, connector->port, crtc_state->pbn); @@ -104,8 +129,8 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder *encoder, } } - /* Despite slots are non-zero, we still failed the atomic check */ - if (ret && slots >= 0) + /* We failed to find a proper bpp/timeslots, return error */ + if (ret) slots = ret; if (slots < 0) {