From 1b58e7d454035355aaa0f29d31366669c13643e7 Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Fri, 5 Apr 2019 10:19:31 +0300 Subject: [PATCH] drm/i915/dp: revert back to max link rate and lane count on eDP MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Cc: Jani Nikula Commit 7769db588384 ("drm/i915/dp: optimize eDP 1.4+ link config fast and narrow") started to optize the eDP 1.4+ link config, both per spec and as preparation for display stream compression support. Sadly, we again face panels that flat out fail with parameters they claim to support. Revert, and go back to the drawing board. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109959 Fixes: 7769db588384 ("drm/i915/dp: optimize eDP 1.4+ link config fast and narrow") Cc: Ville Syrjälä Cc: Manasi Navare Cc: Rodrigo Vivi Cc: Matt Atwood Cc: "Lee, Shawn C" Cc: Dave Airlie Cc: intel-gfx@lists.freedesktop.org Cc: # v5.0+ Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_dp.c | 69 +++++---------------------------- 1 file changed, 10 insertions(+), 59 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 22a746..dcd1df 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1845,42 +1845,6 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp, return false; } -/* Optimize link config in order: max bpp, min lanes, min clock */ -static bool -intel_dp_compute_link_config_fast(struct intel_dp *intel_dp, - struct intel_crtc_state *pipe_config, - const struct link_config_limits *limits) -{ - struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode; - int bpp, clock, lane_count; - int mode_rate, link_clock, link_avail; - - for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) { - mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock, - bpp); - - for (lane_count = limits->min_lane_count; - lane_count <= limits->max_lane_count; - lane_count <<= 1) { - for (clock = limits->min_clock; clock <= limits->max_clock; clock++) { - link_clock = intel_dp->common_rates[clock]; - link_avail = intel_dp_max_data_rate(link_clock, - lane_count); - - if (mode_rate <= link_avail) { - pipe_config->lane_count = lane_count; - pipe_config->pipe_bpp = bpp; - pipe_config->port_clock = link_clock; - - return true; - } - } - } - } - - return false; -} - static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc) { int i, num_bpc; @@ -2013,15 +1977,13 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, limits.min_bpp = 6 * 3; limits.max_bpp = intel_dp_compute_bpp(intel_dp, pipe_config); - if (intel_dp_is_edp(intel_dp) && intel_dp->edp_dpcd[0] < DP_EDP_14) { + if (intel_dp_is_edp(intel_dp)) { /* * Use the maximum clock and number of lanes the eDP panel - * advertizes being capable of. The eDP 1.3 and earlier panels - * are generally designed to support only a single clock and - * lane configuration, and typically these values correspond to - * the native resolution of the panel. With eDP 1.4 rate select - * and DSC, this is decreasingly the case, and we need to be - * able to select less than maximum link config. + * advertizes being capable of. The panels are generally + * designed to support only a single clock and lane + * configuration, and typically these values correspond to the + * native resolution of the panel. */ limits.min_lane_count = limits.max_lane_count; limits.min_clock = limits.max_clock; @@ -2035,22 +1997,11 @@ intel_dp_compute_link_config(struct intel_encoder *encoder, intel_dp->common_rates[limits.max_clock], limits.max_bpp, adjusted_mode->crtc_clock); - if (intel_dp_is_edp(intel_dp)) - /* - * Optimize for fast and narrow. eDP 1.3 section 3.3 and eDP 1.4 - * section A.1: "It is recommended that the minimum number of - * lanes be used, using the minimum link rate allowed for that - * lane configuration." - * - * Note that we use the max clock and lane count for eDP 1.3 and - * earlier, and fast vs. wide is irrelevant. - */ - ret = intel_dp_compute_link_config_fast(intel_dp, pipe_config, - &limits); - else - /* Optimize for slow and wide. */ - ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, - &limits); + /* + * Optimize for slow and wide. This is the place to add alternative + * optimization policy. + */ + ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, &limits); /* enable compression if the mode doesn't fit available BW */ if (!ret) { -- 2.20.1