disp: msm: dp: take port refcount for MST sim ports

The single "port" refcount has been split in 2 on 5.4.  MST sim
layer is only getting the topology refcount but never initializes
or obtains references for the memory allocated for this port.
Add the new refcount logic required on 5.4 to MST sim layer.

Change-Id: I6e25c048fa26352c4fb718996514a1ca91432408
Signed-off-by: Steve Cohen <[email protected]>
Signed-off-by: Rajkumar Subbiah <[email protected]>

msm/dp/dp_mst_drm.c

@@ -185,14 +185,28 @@ static void dp_mst_sim_destroy_port(struct kref *ref)
 
 	if (port->connector) {
 		mutex_lock(&mgr->destroy_connector_lock);
-		kref_get(&port->parent->topology_kref);
 		list_add(&port->next, &mgr->destroy_connector_list);
 		mutex_unlock(&mgr->destroy_connector_lock);
 		schedule_work(&mgr->destroy_connector_work);
 		return;
-	} else {
-		kfree(port);
 	}
+
+	drm_dp_mst_put_port_malloc(port);
+}
+
+static void dp_mst_sim_topology_get_port(struct drm_dp_mst_port *port)
+{
+	WARN_ON(kref_read(&port->topology_kref) == 0);
+	kref_get(&port->topology_kref);
+	DP_MST_DEBUG("get port %p topology(%d)\n", port,
+			kref_read(&port->topology_kref));
+}
+
+static void dp_mst_sim_topology_put_port(struct drm_dp_mst_port *port)
+{
+	DP_MST_DEBUG("put port %p topology(%d)\n", port,
+			kref_read(&port->topology_kref) - 1);
+	kref_put(&port->topology_kref, dp_mst_sim_destroy_port);
 }
 
 /* DRM DP MST Framework simulator OPs */
@@ -208,12 +222,19 @@ static void dp_mst_sim_add_port(struct dp_mst_private *mst,
 	if (!port)
 		return;
 	kref_init(&port->topology_kref);
+	kref_init(&port->malloc_kref);
 	port->parent = mstb;
 	port->port_num = port_msg->port_number;
 	port->mgr = mstb->mgr;
 	port->aux.name = dp_mst.caps.drm_aux->name;
 	port->aux.dev = mst->dp_display->drm_dev->dev;
 
+	/*
+	 * Make sure the memory allocation for our parent branch stays
+	 * around until our own memory allocation is released
+	 */
+	kref_get(&mstb->malloc_kref);
+
 	port->pdt = port_msg->peer_device_type;
 	port->input = port_msg->input_port;
 	port->mcs = port_msg->mcs;
@@ -224,7 +245,7 @@ static void dp_mst_sim_add_port(struct dp_mst_private *mst,
 	port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
 
 	mutex_lock(&mstb->mgr->lock);
-	kref_get(&port->topology_kref);
+	dp_mst_sim_topology_get_port(port);
 	list_add(&port->next, &mstb->ports);
 	mutex_unlock(&mstb->mgr->lock);
 
@@ -239,14 +260,14 @@ static void dp_mst_sim_add_port(struct dp_mst_private *mst,
 			mutex_lock(&mstb->mgr->lock);
 			list_del(&port->next);
 			mutex_unlock(&mstb->mgr->lock);
-			kref_put(&port->topology_kref, dp_mst_sim_destroy_port);
+			dp_mst_sim_topology_put_port(port);
 			goto put_port;
 		}
 		(*mstb->mgr->cbs->register_connector)(port->connector);
 	}
 
 put_port:
-	kref_put(&port->topology_kref, dp_mst_sim_destroy_port);
+	dp_mst_sim_topology_put_port(port);
 }
 
 static void dp_mst_sim_link_probe_work(struct work_struct *work)
@@ -257,6 +278,8 @@ static void dp_mst_sim_link_probe_work(struct work_struct *work)
 	u8 cnt, i;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
+
 	sim = container_of(work, struct dp_mst_sim_mode, probe_work);
 	mst = container_of(sim, struct dp_mst_private, simulator);
 
@@ -423,14 +446,21 @@ static int dp_mst_sim_topology_mgr_set_mst(
 	struct dp_mst_private *mst = container_of(mgr,
 			struct dp_mst_private, mst_mgr);
 
+	/*
+	 * Setting mst off on the mgr initiates shutdown of the branch device.
+	 * Moving the disable to bridge disable in order to make sure the
+	 * connector is valid till the hpd notification is completed.
+	 */
+	if (!mst_state)
+		return 0;
+
 	rc = drm_dp_mst_topology_mgr_set_mst(mgr, mst_state);
 	if (rc < 0) {
 		DRM_ERROR("unable to set mst topology mgr, rc: %d\n", rc);
 		return rc;
 	}
 
-	if (mst_state)
-		queue_work(system_long_wq, &mst->simulator.probe_work);
+	queue_work(system_long_wq, &mst->simulator.probe_work);
 
 	mst->simulator.mst_state = mst_state;
 	return 0;
@@ -509,7 +539,7 @@ static void dp_mst_sim_handle_hpd_irq(void *dp_display,
 			}
 		}
 
-		kref_put(&port->topology_kref, dp_mst_sim_destroy_port);
+		dp_mst_sim_topology_put_port(port);
 	}
 }
 
@@ -605,6 +635,7 @@ static int dp_mst_bridge_attach(struct drm_bridge *dp_bridge)
 	struct dp_mst_bridge *bridge;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	if (!dp_bridge) {
 		DP_ERR("Invalid params\n");
@@ -628,6 +659,7 @@ static bool dp_mst_bridge_mode_fixup(struct drm_bridge *drm_bridge,
 	struct dp_display *dp;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	if (!drm_bridge || !mode || !adjusted_mode) {
 		DP_ERR("Invalid params\n");
@@ -667,6 +699,7 @@ static int _dp_mst_compute_config(struct drm_atomic_state *state,
 	int rc = 0;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	pbn = mst->mst_fw_cbs->calc_pbn_mode(mode);
 
@@ -679,6 +712,7 @@ static int _dp_mst_compute_config(struct drm_atomic_state *state,
 	}
 
 	DP_MST_DEBUG("exit\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT);
 
 	return rc;
 }
@@ -750,6 +784,9 @@ static void _dp_mst_bridge_pre_enable_part1(struct dp_mst_bridge *dp_bridge)
 	bool ret;
 	int pbn, slots;
 
+	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
+
 	/* skip mst specific disable operations during suspend */
 	if (mst->state == PM_SUSPEND) {
 		dp_display->wakeup_phy_layer(dp_display, true);
@@ -759,6 +796,14 @@ static void _dp_mst_bridge_pre_enable_part1(struct dp_mst_bridge *dp_bridge)
 		return;
 	}
 
+	/*
+	 * Take a reference to the port topology to make sure the port object
+	 * is available while waiting for the connector to be cleaned up after
+	 * hpd low. This reference will be released in the disable path.
+	 */
+	if (mst->simulator.mst_state)
+		dp_mst_sim_topology_get_port(port);
+
 	pbn = mst->mst_fw_cbs->calc_pbn_mode(&dp_bridge->dp_mode);
 
 	slots = mst->mst_fw_cbs->find_vcpi_slots(&mst->mst_mgr, pbn);
@@ -788,6 +833,7 @@ static void _dp_mst_bridge_pre_enable_part2(struct dp_mst_bridge *dp_bridge)
 	struct dp_mst_private *mst = dp_display->dp_mst_prv_info;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	/* skip mst specific disable operations during suspend */
 	if (mst->state == PM_SUSPEND)
@@ -810,6 +856,7 @@ static void _dp_mst_bridge_pre_disable_part1(struct dp_mst_bridge *dp_bridge)
 	struct drm_dp_mst_port *port = c_conn->mst_port;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	/* skip mst specific disable operations during suspend */
 	if (mst->state == PM_SUSPEND) {
@@ -834,8 +881,10 @@ static void _dp_mst_bridge_pre_disable_part2(struct dp_mst_bridge *dp_bridge)
 	struct sde_connector *c_conn =
 		to_sde_connector(dp_bridge->connector);
 	struct drm_dp_mst_port *port = c_conn->mst_port;
+	int rc = 0;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	/* skip mst specific disable operations during suspend */
 	if (mst->state == PM_SUSPEND) {
@@ -849,8 +898,21 @@ static void _dp_mst_bridge_pre_disable_part2(struct dp_mst_bridge *dp_bridge)
 
 	mst->mst_fw_cbs->update_payload_part2(&mst->mst_mgr);
 
+	port->vcpi.vcpi = dp_bridge->vcpi;
 	mst->mst_fw_cbs->deallocate_vcpi(&mst->mst_mgr, port);
 
+	if (mst->simulator.mst_state) {
+		rc = drm_dp_mst_topology_mgr_set_mst(&mst->mst_mgr, false);
+		if (rc < 0)
+			DRM_WARN("unable to set mst topology mgr, rc: %d\n",
+					rc);
+
+		/* release the reference taken during pre_enable */
+		dp_mst_sim_topology_put_port(port);
+
+		mst->simulator.mst_state = false;
+	}
+
 	dp_bridge->vcpi = 0;
 	dp_bridge->pbn = 0;
 
@@ -870,6 +932,9 @@ static void dp_mst_bridge_pre_enable(struct drm_bridge *drm_bridge)
 		return;
 	}
 
+	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
+
 	bridge = to_dp_mst_bridge(drm_bridge);
 	dp = bridge->display;
 
@@ -941,6 +1006,9 @@ static void dp_mst_bridge_enable(struct drm_bridge *drm_bridge)
 		return;
 	}
 
+	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
+
 	dp = bridge->display;
 
 	rc = dp->post_enable(dp, bridge->dp_panel);
@@ -966,6 +1034,9 @@ static void dp_mst_bridge_disable(struct drm_bridge *drm_bridge)
 		return;
 	}
 
+	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
+
 	bridge = to_dp_mst_bridge(drm_bridge);
 	if (!bridge->connector) {
 		DP_ERR("Invalid connector\n");
@@ -1012,6 +1083,9 @@ static void dp_mst_bridge_post_disable(struct drm_bridge *drm_bridge)
 		return;
 	}
 
+	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
+
 	dp = bridge->display;
 	mst = dp->dp_mst_prv_info;
 
@@ -1049,6 +1123,7 @@ static void dp_mst_bridge_mode_set(struct drm_bridge *drm_bridge,
 	struct dp_display *dp;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	if (!drm_bridge || !mode || !adjusted_mode) {
 		DP_ERR("Invalid params\n");
@@ -1198,6 +1273,7 @@ dp_mst_connector_detect(struct drm_connector *connector, bool force,
 	struct dp_mst_connector mst_conn;
 
 	DP_MST_DEBUG("enter:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	status = mst->mst_fw_cbs->detect_port(connector,
 			&mst->mst_mgr,
@@ -1214,6 +1290,7 @@ dp_mst_connector_detect(struct drm_connector *connector, bool force,
 			connector->base.id, status);
 
 	DP_MST_DEBUG("exit:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT);
 
 	return status;
 }
@@ -1228,6 +1305,7 @@ static int dp_mst_connector_get_modes(struct drm_connector *connector,
 	int rc = 0;
 
 	DP_MST_DEBUG("enter:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	edid = mst->mst_fw_cbs->get_edid(connector, &mst->mst_mgr,
 			c_conn->mst_port);
@@ -1239,6 +1317,7 @@ static int dp_mst_connector_get_modes(struct drm_connector *connector,
 	DP_MST_DEBUG("mst connector get modes. id: %d\n", connector->base.id);
 
 	DP_MST_DEBUG("exit:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT);
 
 	return rc;
 }
@@ -1308,6 +1387,7 @@ int dp_mst_connector_get_info(struct drm_connector *connector,
 	enum drm_connector_status status = connector_status_unknown;
 
 	DP_MST_DEBUG("enter:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	rc = dp_connector_get_info(connector, info, display);
 
@@ -1324,6 +1404,7 @@ int dp_mst_connector_get_info(struct drm_connector *connector,
 			connector->base.id, status, rc);
 
 	DP_MST_DEBUG("exit:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT);
 
 	return rc;
 }
@@ -1337,6 +1418,7 @@ int dp_mst_connector_get_mode_info(struct drm_connector *connector,
 	int rc;
 
 	DP_MST_DEBUG("enter:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	rc = dp_connector_get_mode_info(connector, drm_mode, mode_info,
 			display, avail_res);
@@ -1345,6 +1427,7 @@ int dp_mst_connector_get_mode_info(struct drm_connector *connector,
 			connector->base.id, rc);
 
 	DP_MST_DEBUG("exit:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT);
 
 	return rc;
 }
@@ -1420,6 +1503,7 @@ static int dp_mst_connector_atomic_check(struct drm_connector *connector,
 	struct dp_display_mode dp_mode;
 
 	DP_MST_DEBUG("enter:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	/*
 	 * Skip atomic check during mst suspend, to avoid mismanagement of
@@ -1508,6 +1592,7 @@ static int dp_mst_connector_config_hdr(struct drm_connector *connector,
 	int rc;
 
 	DP_MST_DEBUG("enter:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	rc = dp_connector_config_hdr(connector, display, c_state);
 
@@ -1515,6 +1600,7 @@ static int dp_mst_connector_config_hdr(struct drm_connector *connector,
 			connector->base.id, rc);
 
 	DP_MST_DEBUG("exit:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT);
 
 	return rc;
 }
@@ -1523,10 +1609,16 @@ static void dp_mst_connector_pre_destroy(struct drm_connector *connector,
 		void *display)
 {
 	struct dp_display *dp_display = display;
+	struct sde_connector *c_conn = to_sde_connector(connector);
 
 	DP_MST_DEBUG("enter:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
+
+	drm_dp_mst_put_port_malloc(c_conn->mst_port);
+
 	dp_display->mst_connector_uninstall(dp_display, connector);
 	DP_MST_DEBUG("exit:\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_EXIT);
 }
 
 /* DRM MST callbacks */
@@ -1556,6 +1648,7 @@ dp_mst_add_connector(struct drm_dp_mst_topology_mgr *mgr,
 	int rc, i;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	dp_mst = container_of(mgr, struct dp_mst_private, mst_mgr);
 
@@ -1589,6 +1682,7 @@ dp_mst_add_connector(struct drm_dp_mst_topology_mgr *mgr,
 
 	c_conn = to_sde_connector(connector);
 	c_conn->mst_port = port;
+	drm_dp_mst_get_port_malloc(c_conn->mst_port);
 
 	if (connector->funcs->reset)
 		connector->funcs->reset(connector);
@@ -1614,6 +1708,7 @@ dp_mst_add_connector(struct drm_dp_mst_topology_mgr *mgr,
 static void dp_mst_register_connector(struct drm_connector *connector)
 {
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	connector->status = connector->funcs->detect(connector, false);
 
@@ -1626,6 +1721,7 @@ static void dp_mst_destroy_connector(struct drm_dp_mst_topology_mgr *mgr,
 					   struct drm_connector *connector)
 {
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	DP_MST_INFO_LOG("destroy mst connector id:%d\n", connector->base.id);
 
@@ -1777,6 +1873,7 @@ dp_mst_add_fixed_connector(struct drm_dp_mst_topology_mgr *mgr,
 	int i, enc_idx;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	dp_mst = container_of(mgr, struct dp_mst_private, mst_mgr);
 
@@ -1828,6 +1925,7 @@ static void dp_mst_register_fixed_connector(struct drm_connector *connector)
 	int i;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	/* skip connector registered for fixed topology ports */
 	for (i = 0; i < MAX_DP_MST_DRM_BRIDGES; i++) {
@@ -1848,6 +1946,7 @@ static void dp_mst_destroy_fixed_connector(struct drm_dp_mst_topology_mgr *mgr,
 	int i;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	dp_mst = container_of(mgr, struct dp_mst_private, mst_mgr);
 
@@ -1885,6 +1984,7 @@ dp_mst_drm_fixed_connector_init(struct dp_display *dp_display,
 	int rc;
 
 	DP_MST_DEBUG("enter\n");
+	SDE_EVT32_EXTERNAL(SDE_EVTLOG_FUNC_ENTRY);
 
 	dev = dp_display->drm_dev;