drm/amd/display: Add display only once.

[Why]
We call add display multiple times because DESIRED->ENABLED cannot
happen instantaneously. We can't compare the new_state/old_state to
avoid this because on unplug we set the state to DESIRED and on hotplug
the state will still be DESIRED.

[How]
Add a flag to dm_connector_state to keep track of when to enable or
disable HDCP
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Zhan Liu <zhan.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -2401,6 +2401,7 @@ static void handle_hpd_irq(void *param)
 	enum dc_connection_type new_connection_type = dc_connection_none;
 #ifdef CONFIG_DRM_AMD_DC_HDCP
 	struct amdgpu_device *adev = drm_to_adev(dev);
+	struct dm_connector_state *dm_con_state = to_dm_connector_state(connector->state);
 #endif
 
 	/*
@@ -2410,8 +2411,10 @@ static void handle_hpd_irq(void *param)
 	mutex_lock(&aconnector->hpd_lock);
 
 #ifdef CONFIG_DRM_AMD_DC_HDCP
-	if (adev->dm.hdcp_workqueue)
+	if (adev->dm.hdcp_workqueue) {
 		hdcp_reset_display(adev->dm.hdcp_workqueue, aconnector->dc_link->link_index);
+		dm_con_state->update_hdcp = true;
+	}
 #endif
 	if (aconnector->fake_enable)
 		aconnector->fake_enable = false;
@@ -7233,6 +7236,7 @@ static bool is_content_protection_different(struct drm_connector_state *state,
 					    const struct drm_connector *connector, struct hdcp_workqueue *hdcp_w)
 {
 	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
+	struct dm_connector_state *dm_con_state = to_dm_connector_state(connector->state);
 
 	if (old_state->hdcp_content_type != state->hdcp_content_type &&
 	    state->content_protection != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
@@ -7255,14 +7259,16 @@ static bool is_content_protection_different(struct drm_connector_state *state,
 	/* Check if something is connected/enabled, otherwise we start hdcp but nothing is connected/enabled
 	 * hot-plug, headless s3, dpms
 	 */
-	if (state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED && connector->dpms == DRM_MODE_DPMS_ON &&
-	    aconnector->dc_sink != NULL)
+	if (dm_con_state->update_hdcp && state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
+	    connector->dpms == DRM_MODE_DPMS_ON && aconnector->dc_sink != NULL) {
+		dm_con_state->update_hdcp = false;
 		return true;
+	}
 
 	if (old_state->content_protection == state->content_protection)
 		return false;
 
-	if (state->content_protection == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
+	if (state->content_protection != DRM_MODE_CONTENT_PROTECTION_ENABLED)
 		return true;
 
 	return false;
@@ -8189,6 +8195,7 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 		    connector->state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
 			hdcp_reset_display(adev->dm.hdcp_workqueue, aconnector->dc_link->link_index);
 			new_con_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+			dm_new_con_state->update_hdcp = true;
 			continue;
 		}
 

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

@@ -483,6 +483,9 @@ struct dm_connector_state {
 	uint8_t underscan_hborder;
 	bool underscan_enable;
 	bool freesync_capable;
+#ifdef CONFIG_DRM_AMD_DC_HDCP
+	bool update_hdcp;
+#endif
 	uint8_t abm_level;
 	int vcpi_slots;
 	uint64_t pbn;