drm/amd/display: Disable boot optimizations if ILR optimzation is required

[Why]
VBIOS currently sets the max link rate found in eDP 1.4 SUPPORTED_LINK_RATES table
If eDP fastboot optimizations are enabled, the link rate remains at max after init

[How]
Determine optimal link rate during boot, disable seamless boot
and eDP fastboot optimizations if link rate optimization is required
Signed-off-by: Michael Strauss <michael.strauss@amd.com>
Acked-by: Bindu Ramamurthy <bindur12@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -55,6 +55,7 @@
 #include "link_encoder.h"
 #include "link_enc_cfg.h"
 
+#include "dc_link.h"
 #include "dc_link_ddc.h"
 #include "dm_helpers.h"
 #include "mem_input.h"
@@ -1429,6 +1430,10 @@ bool dc_validate_seamless_boot_timing(const struct dc *dc,
 		return false;
 	}
 
+	if (is_edp_ilr_optimization_required(link, crtc_timing)) {
+		return false;
+	}
+
 	return true;
 }
 

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -4718,3 +4718,46 @@ bool dc_link_set_default_brightness_aux(struct dc_link *link)
 	}
 	return false;
 }
+
+bool is_edp_ilr_optimization_required(struct dc_link *link, struct dc_crtc_timing *crtc_timing)
+{
+	struct dc_link_settings link_setting;
+	uint8_t link_bw_set;
+	uint8_t link_rate_set;
+	uint32_t req_bw;
+	union lane_count_set lane_count_set = { {0} };
+
+	ASSERT(link || crtc_timing); // invalid input
+
+	if (link->dpcd_caps.edp_supported_link_rates_count == 0 ||
+			!link->dc->debug.optimize_edp_link_rate)
+		return false;
+
+
+	// Read DPCD 00100h to find if standard link rates are set
+	core_link_read_dpcd(link, DP_LINK_BW_SET,
+				&link_bw_set, sizeof(link_bw_set));
+
+	if (link_bw_set)
+		return true;
+
+	// Read DPCD 00115h to find the edp link rate set used
+	core_link_read_dpcd(link, DP_LINK_RATE_SET,
+			    &link_rate_set, sizeof(link_rate_set));
+
+	// Read DPCD 00101h to find out the number of lanes currently set
+	core_link_read_dpcd(link, DP_LANE_COUNT_SET,
+				&lane_count_set.raw, sizeof(lane_count_set));
+
+	req_bw = dc_bandwidth_in_kbps_from_timing(crtc_timing);
+
+	decide_edp_link_settings(link, &link_setting, req_bw);
+
+	if (link->dpcd_caps.edp_supported_link_rates[link_rate_set] != link_setting.link_rate ||
+			lane_count_set.bits.LANE_COUNT_SET != link_setting.lane_count)
+		return true;
+
+	return false;
+}
+
+

drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c

@@ -48,6 +48,7 @@
 #include "stream_encoder.h"
 #include "link_encoder.h"
 #include "link_hwss.h"
+#include "dc_link_dp.h"
 #include "clock_source.h"
 #include "clk_mgr.h"
 #include "abm.h"
@@ -1714,8 +1715,9 @@ void dce110_enable_accelerated_mode(struct dc *dc, struct dc_state *context)
 				/* Set optimization flag on eDP stream*/
 				if (edp_stream_num && edp_link->link_status.link_active) {
 					edp_stream = edp_streams[0];
-					edp_stream->apply_edp_fast_boot_optimization = true;
-					can_apply_edp_fast_boot = true;
+					can_apply_edp_fast_boot = !is_edp_ilr_optimization_required(edp_stream->link, &edp_stream->timing);
+					edp_stream->apply_edp_fast_boot_optimization = can_apply_edp_fast_boot;
+
 					break;
 				}
 			}

drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h

@@ -71,6 +71,8 @@ void detect_edp_sink_caps(struct dc_link *link);
 
 bool is_dp_active_dongle(const struct dc_link *link);
 
+bool is_edp_ilr_optimization_required(struct dc_link *link, struct dc_crtc_timing *crtc_timing);
+
 void dp_enable_mst_on_sink(struct dc_link *link, bool enable);
 
 enum dp_panel_mode dp_get_panel_mode(struct dc_link *link);