diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 115662c2f048..8233f2aea665 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -767,8 +767,10 @@ intel_dp_compute_config(struct intel_encoder *encoder, struct intel_crtc *intel_crtc = encoder->new_crtc; struct intel_connector *intel_connector = intel_dp->attached_connector; int lane_count, clock; + int min_lane_count = 1; int max_lane_count = intel_dp_max_lane_count(intel_dp); /* Conveniently, the link BW constants become indices with a shift...*/ + int min_clock = 0; int max_clock = intel_dp_max_link_bw(intel_dp) >> 3; int bpp, mode_rate; static int bws[] = { DP_LINK_BW_1_62, DP_LINK_BW_2_7, DP_LINK_BW_5_4 }; @@ -801,19 +803,33 @@ intel_dp_compute_config(struct intel_encoder *encoder, /* Walk through all bpp values. Luckily they're all nicely spaced with 2 * bpc in between. */ bpp = pipe_config->pipe_bpp; - if (is_edp(intel_dp) && dev_priv->vbt.edp_bpp && - dev_priv->vbt.edp_bpp < bpp) { - DRM_DEBUG_KMS("clamping bpp for eDP panel to BIOS-provided %i\n", - dev_priv->vbt.edp_bpp); - bpp = dev_priv->vbt.edp_bpp; + if (is_edp(intel_dp)) { + if (dev_priv->vbt.edp_bpp && dev_priv->vbt.edp_bpp < bpp) { + DRM_DEBUG_KMS("clamping bpp for eDP panel to BIOS-provided %i\n", + dev_priv->vbt.edp_bpp); + bpp = dev_priv->vbt.edp_bpp; + } + + if (dev_priv->vbt.edp_lanes) { + min_lane_count = min(dev_priv->vbt.edp_lanes, + max_lane_count); + DRM_DEBUG_KMS("using min %u lanes per VBT\n", + min_lane_count); + } + + if (dev_priv->vbt.edp_rate) { + min_clock = min(dev_priv->vbt.edp_rate >> 3, max_clock); + DRM_DEBUG_KMS("using min %02x link bw per VBT\n", + bws[min_clock]); + } } for (; bpp >= 6*3; bpp -= 2*3) { mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock, bpp); - for (lane_count = 1; lane_count <= max_lane_count; lane_count <<= 1) { - for (clock = 0; clock <= max_clock; clock++) { + for (lane_count = min_lane_count; lane_count <= max_lane_count; lane_count <<= 1) { + for (clock = min_clock; clock <= max_clock; clock++) { link_clock = drm_dp_bw_code_to_link_rate(bws[clock]); link_avail = intel_dp_max_data_rate(link_clock, lane_count);