From 56071a207602a451f0c46d3dcc8379b59ef576e2 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Tue, 6 May 2014 14:56:52 +0300 Subject: [PATCH] drm/i915: use lane count and link rate from VBT as minimums for eDP Most likely the minimums for both should be enough for enabling the native resolution on the eDP, and we'll end up using the predetermined optimal link config for the panel. v2: Add debug prints. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=73539 Tested-by: Markus Blank-Burian Reviewed-by: Damien Lespiau Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_dp.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) 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); -- 2.20.1