drm/amd/display: add config option for eDP hotplug detection

[Why]
Some custom platforms use eDP hotplug events to notify panel
capability changes that should be reported

[How]
Add a DC config option that unblocks eDP hotplug events
Signed-off-by: Yi-Ling Chen <Yi-Ling.Chen2@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@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_link.c

@@ -904,9 +904,10 @@ static bool dc_link_detect_helper(struct dc_link *link,
 	if (dc_is_virtual_signal(link->connector_signal))
 		return false;
 
-	if ((link->connector_signal == SIGNAL_TYPE_LVDS ||
-	     link->connector_signal == SIGNAL_TYPE_EDP) &&
-	    link->local_sink) {
+	if (((link->connector_signal == SIGNAL_TYPE_LVDS ||
+		link->connector_signal == SIGNAL_TYPE_EDP) &&
+		(!link->dc->config.allow_edp_hotplug_detection)) &&
+		link->local_sink) {
 		// need to re-write OUI and brightness in resume case
 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
 			dpcd_set_source_specific_data(link);
@@ -1501,7 +1502,8 @@ static bool dc_link_construct(struct dc_link *link,
 		link->connector_signal = SIGNAL_TYPE_EDP;
 
 		if (link->hpd_gpio) {
-			link->irq_source_hpd = DC_IRQ_SOURCE_INVALID;
+			if (!link->dc->config.allow_edp_hotplug_detection)
+				link->irq_source_hpd = DC_IRQ_SOURCE_INVALID;
 			link->irq_source_hpd_rx =
 					dal_irq_get_rx_source(link->hpd_gpio);
 		}

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

@@ -303,6 +303,7 @@ struct dc_config {
 	bool multi_mon_pp_mclk_switch;
 	bool disable_dmcu;
 	bool enable_4to1MPC;
+	bool allow_edp_hotplug_detection;
 #if defined(CONFIG_DRM_AMD_DC_DCN)
 	bool clamp_min_dcfclk;
 #endif