drm/amd/display: refactor ILR to make it work

[Why]
Current ILR toggle is on/off as a part of panel
config for new function, which breaks original
ILR logic

[How]
Refactor ILR and take panel config into account
Reviewed-by: Anthony Koo <anthony.koo@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Sherry Wang <yao.wang1@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/link/link_detection.c

@@ -1166,6 +1166,12 @@ static bool detect_link_and_local_sink(struct dc_link *link,
 			dm_helpers_init_panel_settings(dc_ctx, &link->panel_config, sink);
 			// Override dc_panel_config if system has specific settings
 			dm_helpers_override_panel_settings(dc_ctx, &link->panel_config);
+
+			//sink only can use supported link rate table, we are foreced to enable it
+			if (link->reported_link_cap.link_rate == LINK_RATE_UNKNOWN)
+				link->panel_config.ilr.optimize_edp_link_rate = true;
+			if (edp_is_ilr_optimization_enabled(link))
+				link->reported_link_cap.link_rate = get_max_link_rate_from_ilr_table(link);
 		}
 
 	} else {

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c

@@ -707,8 +707,7 @@ bool edp_decide_link_settings(struct dc_link *link,
 	 * edp_supported_link_rates_count is only valid for eDP v1.4 or higher.
 	 * Per VESA eDP spec, "The DPCD revision for eDP v1.4 is 13h"
 	 */
-	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_13 ||
-			link->dpcd_caps.edp_supported_link_rates_count == 0) {
+	if (!edp_is_ilr_optimization_enabled(link)) {
 		*link_setting = link->verified_link_cap;
 		return true;
 	}
@@ -772,8 +771,7 @@ bool decide_edp_link_settings_with_dsc(struct dc_link *link,
 	 * edp_supported_link_rates_count is only valid for eDP v1.4 or higher.
 	 * Per VESA eDP spec, "The DPCD revision for eDP v1.4 is 13h"
 	 */
-	if ((link->dpcd_caps.dpcd_rev.raw < DPCD_REV_13 ||
-			link->dpcd_caps.edp_supported_link_rates_count == 0)) {
+	if (!edp_is_ilr_optimization_enabled(link)) {
 		/* for DSC enabled case, we search for minimum lane count */
 		memset(&initial_link_setting, 0, sizeof(initial_link_setting));
 		initial_link_setting.lane_count = LANE_COUNT_ONE;
@@ -1938,9 +1936,7 @@ void detect_edp_sink_caps(struct dc_link *link)
 	 * edp_supported_link_rates_count is only valid for eDP v1.4 or higher.
 	 * Per VESA eDP spec, "The DPCD revision for eDP v1.4 is 13h"
 	 */
-	if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_13 &&
-			(link->panel_config.ilr.optimize_edp_link_rate ||
-			link->reported_link_cap.link_rate == LINK_RATE_UNKNOWN)) {
+	if (link->dpcd_caps.dpcd_rev.raw >= DPCD_REV_13) {
 		// Read DPCD 00010h - 0001Fh 16 bytes at one shot
 		core_link_read_dpcd(link, DP_SUPPORTED_LINK_RATES,
 							supported_link_rates, sizeof(supported_link_rates));
@@ -1958,12 +1954,10 @@ void detect_edp_sink_caps(struct dc_link *link)
 				link_rate = linkRateInKHzToLinkRateMultiplier(link_rate_in_khz);
 				link->dpcd_caps.edp_supported_link_rates[link->dpcd_caps.edp_supported_link_rates_count] = link_rate;
 				link->dpcd_caps.edp_supported_link_rates_count++;
-
-				if (link->reported_link_cap.link_rate < link_rate)
-					link->reported_link_cap.link_rate = link_rate;
 			}
 		}
 	}
+
 	core_link_read_dpcd(link, DP_EDP_BACKLIGHT_ADJUSTMENT_CAP,
 						&backlight_adj_cap, sizeof(backlight_adj_cap));
 

drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c

@@ -302,6 +302,24 @@ bool set_cached_brightness_aux(struct dc_link *link)
 		return set_default_brightness_aux(link);
 	return false;
 }
+bool edp_is_ilr_optimization_enabled(struct dc_link *link)
+{
+	if (link->dpcd_caps.edp_supported_link_rates_count == 0 || !link->panel_config.ilr.optimize_edp_link_rate)
+		return false;
+	return true;
+}
+
+enum dc_link_rate get_max_link_rate_from_ilr_table(struct dc_link *link)
+{
+	enum dc_link_rate link_rate = link->reported_link_cap.link_rate;
+
+	for (int i = 0; i < link->dpcd_caps.edp_supported_link_rates_count; i++) {
+		if (link_rate < link->dpcd_caps.edp_supported_link_rates[i])
+			link_rate = link->dpcd_caps.edp_supported_link_rates[i];
+	}
+
+	return link_rate;
+}
 
 bool edp_is_ilr_optimization_required(struct dc_link *link,
 		struct dc_crtc_timing *crtc_timing)
@@ -314,8 +332,7 @@ bool edp_is_ilr_optimization_required(struct dc_link *link,
 
 	ASSERT(link || crtc_timing); // invalid input
 
-	if (link->dpcd_caps.edp_supported_link_rates_count == 0 ||
-			!link->panel_config.ilr.optimize_edp_link_rate)
+	if (!edp_is_ilr_optimization_enabled(link))
 		return false;
 
 

drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.h

@@ -64,6 +64,8 @@ bool edp_get_replay_state(const struct dc_link *link, uint64_t *state);
 bool edp_wait_for_t12(struct dc_link *link);
 bool edp_is_ilr_optimization_required(struct dc_link *link,
        struct dc_crtc_timing *crtc_timing);
+bool edp_is_ilr_optimization_enabled(struct dc_link *link);
+enum dc_link_rate get_max_link_rate_from_ilr_table(struct dc_link *link);
 bool edp_backlight_enable_aux(struct dc_link *link, bool enable);
 void edp_add_delay_for_T9(struct dc_link *link);
 bool edp_receiver_ready_T9(struct dc_link *link);