1 files changed, 197 insertions, 146 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 38bf111e5f9b..4b255e25e4a1 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -736,6 +736,10 @@ static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
 	if (msg->curchunk_idx >= msg->curchunk_len) {
 		/* do CRC */
 		crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
+		if (crc4 != msg->chunk[msg->curchunk_len - 1])
+			print_hex_dump(KERN_DEBUG, "wrong crc",
+				       DUMP_PREFIX_NONE, 16, 1,
+				       msg->chunk,  msg->curchunk_len, false);
 		/* copy chunk into bigger msg */
 		memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
 		msg->curlen += msg->curchunk_len - 1;
@@ -1035,7 +1039,8 @@ static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
 	}
 }
 
-static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
+static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
+			     u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
 {
 	struct drm_dp_sideband_msg_req_body req;
 
@@ -1045,17 +1050,14 @@ static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32
 	req.u.dpcd_write.num_bytes = num_bytes;
 	req.u.dpcd_write.bytes = bytes;
 	drm_dp_encode_sideband_req(&req, msg);
-
-	return 0;
 }
 
-static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
+static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
 {
 	struct drm_dp_sideband_msg_req_body req;
 
 	req.req_type = DP_LINK_ADDRESS;
 	drm_dp_encode_sideband_req(&req, msg);
-	return 0;
 }
 
 static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
@@ -1067,7 +1069,8 @@ static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
 	return 0;
 }
 
-static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
+static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
+				     int port_num)
 {
 	struct drm_dp_sideband_msg_req_body req;
 
@@ -1078,10 +1081,11 @@ static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int por
 	return 0;
 }
 
-static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
-				  u8 vcpi, uint16_t pbn,
-				  u8 number_sdp_streams,
-				  u8 *sdp_stream_sink)
+static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
+				   int port_num,
+				   u8 vcpi, uint16_t pbn,
+				   u8 number_sdp_streams,
+				   u8 *sdp_stream_sink)
 {
 	struct drm_dp_sideband_msg_req_body req;
 	memset(&req, 0, sizeof(req));
@@ -1094,11 +1098,10 @@ static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_n
 		   number_sdp_streams);
 	drm_dp_encode_sideband_req(&req, msg);
 	msg->path_msg = true;
-	return 0;
 }
 
-static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
-				  int port_num, bool power_up)
+static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
+				   int port_num, bool power_up)
 {
 	struct drm_dp_sideband_msg_req_body req;
 
@@ -1110,7 +1113,6 @@ static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
 	req.u.port_num.port_number = port_num;
 	drm_dp_encode_sideband_req(&req, msg);
 	msg->path_msg = true;
-	return 0;
 }
 
 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
@@ -1935,73 +1937,90 @@ static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
 	return parent_lct + 1;
 }
 
-static int drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt)
+static bool drm_dp_mst_is_dp_mst_end_device(u8 pdt, bool mcs)
+{
+	switch (pdt) {
+	case DP_PEER_DEVICE_DP_LEGACY_CONV:
+	case DP_PEER_DEVICE_SST_SINK:
+		return true;
+	case DP_PEER_DEVICE_MST_BRANCHING:
+		/* For sst branch device */
+		if (!mcs)
+			return true;
+
+		return false;
+	}
+	return true;
+}
+
+static int
+drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
+		    bool new_mcs)
 {
 	struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 	struct drm_dp_mst_branch *mstb;
 	u8 rad[8], lct;
 	int ret = 0;
 
-	if (port->pdt == new_pdt)
+	if (port->pdt == new_pdt && port->mcs == new_mcs)
 		return 0;
 
 	/* Teardown the old pdt, if there is one */
-	switch (port->pdt) {
-	case DP_PEER_DEVICE_DP_LEGACY_CONV:
-	case DP_PEER_DEVICE_SST_SINK:
-		/*
-		 * If the new PDT would also have an i2c bus, don't bother
-		 * with reregistering it
-		 */
-		if (new_pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
-		    new_pdt == DP_PEER_DEVICE_SST_SINK) {
-			port->pdt = new_pdt;
-			return 0;
-		}
+	if (port->pdt != DP_PEER_DEVICE_NONE) {
+		if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
+			/*
+			 * If the new PDT would also have an i2c bus,
+			 * don't bother with reregistering it
+			 */
+			if (new_pdt != DP_PEER_DEVICE_NONE &&
+			    drm_dp_mst_is_dp_mst_end_device(new_pdt, new_mcs)) {
+				port->pdt = new_pdt;
+				port->mcs = new_mcs;
+				return 0;
+			}
 
-		/* remove i2c over sideband */
-		drm_dp_mst_unregister_i2c_bus(&port->aux);
-		break;
-	case DP_PEER_DEVICE_MST_BRANCHING:
-		mutex_lock(&mgr->lock);
-		drm_dp_mst_topology_put_mstb(port->mstb);
-		port->mstb = NULL;
-		mutex_unlock(&mgr->lock);
-		break;
+			/* remove i2c over sideband */
+			drm_dp_mst_unregister_i2c_bus(&port->aux);
+		} else {
+			mutex_lock(&mgr->lock);
+			drm_dp_mst_topology_put_mstb(port->mstb);
+			port->mstb = NULL;
+			mutex_unlock(&mgr->lock);
+		}
 	}
 
 	port->pdt = new_pdt;
-	switch (port->pdt) {
-	case DP_PEER_DEVICE_DP_LEGACY_CONV:
-	case DP_PEER_DEVICE_SST_SINK:
-		/* add i2c over sideband */
-		ret = drm_dp_mst_register_i2c_bus(&port->aux);
-		break;
+	port->mcs = new_mcs;
 
-	case DP_PEER_DEVICE_MST_BRANCHING:
-		lct = drm_dp_calculate_rad(port, rad);
-		mstb = drm_dp_add_mst_branch_device(lct, rad);
-		if (!mstb) {
-			ret = -ENOMEM;
-			DRM_ERROR("Failed to create MSTB for port %p", port);
-			goto out;
-		}
+	if (port->pdt != DP_PEER_DEVICE_NONE) {
+		if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
+			/* add i2c over sideband */
+			ret = drm_dp_mst_register_i2c_bus(&port->aux);
+		} else {
+			lct = drm_dp_calculate_rad(port, rad);
+			mstb = drm_dp_add_mst_branch_device(lct, rad);
+			if (!mstb) {
+				ret = -ENOMEM;
+				DRM_ERROR("Failed to create MSTB for port %p",
+					  port);
+				goto out;
+			}
 
-		mutex_lock(&mgr->lock);
-		port->mstb = mstb;
-		mstb->mgr = port->mgr;
-		mstb->port_parent = port;
+			mutex_lock(&mgr->lock);
+			port->mstb = mstb;
+			mstb->mgr = port->mgr;
+			mstb->port_parent = port;
 
-		/*
-		 * Make sure this port's memory allocation stays
-		 * around until its child MSTB releases it
-		 */
-		drm_dp_mst_get_port_malloc(port);
-		mutex_unlock(&mgr->lock);
+			/*
+			 * Make sure this port's memory allocation stays
+			 * around until its child MSTB releases it
+			 */
+			drm_dp_mst_get_port_malloc(port);
+			mutex_unlock(&mgr->lock);
 
-		/* And make sure we send a link address for this */
-		ret = 1;
-		break;
+			/* And make sure we send a link address for this */
+			ret = 1;
+		}
 	}
 
 out:
@@ -2044,7 +2063,7 @@ ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
  * sideband messaging as drm_dp_dpcd_write() does for local
  * devices via actual AUX CH.
  *
- * Return: 0 on success, negative error code on failure.
+ * Return: number of bytes written on success, negative error code on failure.
  */
 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
 			      unsigned int offset, void *buffer, size_t size)
@@ -2056,29 +2075,27 @@ ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
 				      offset, size, buffer);
 }
 
-static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
+static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
 {
-	int ret;
+	int ret = 0;
 
 	memcpy(mstb->guid, guid, 16);
 
 	if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
 		if (mstb->port_parent) {
-			ret = drm_dp_send_dpcd_write(
-					mstb->mgr,
-					mstb->port_parent,
-					DP_GUID,
-					16,
-					mstb->guid);
+			ret = drm_dp_send_dpcd_write(mstb->mgr,
+						     mstb->port_parent,
+						     DP_GUID, 16, mstb->guid);
 		} else {
-
-			ret = drm_dp_dpcd_write(
-					mstb->mgr->aux,
-					DP_GUID,
-					mstb->guid,
-					16);
+			ret = drm_dp_dpcd_write(mstb->mgr->aux,
+						DP_GUID, mstb->guid, 16);
 		}
 	}
+
+	if (ret < 16 && ret > 0)
+		return -EPROTO;
+
+	return ret == 16 ? 0 : ret;
 }
 
 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
@@ -2154,15 +2171,14 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
 		goto error;
 	}
 
-	if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
-	     port->pdt == DP_PEER_DEVICE_SST_SINK) &&
-	    port->port_num >= DP_MST_LOGICAL_PORT_0) {
+	if (port->pdt != DP_PEER_DEVICE_NONE &&
+	    drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
 		port->cached_edid = drm_get_edid(port->connector,
 						 &port->aux.ddc);
 		drm_connector_set_tile_property(port->connector);
 	}
 
-	mgr->cbs->register_connector(port->connector);
+	drm_connector_register(port->connector);
 	return;
 
 error:
@@ -2224,6 +2240,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
 	struct drm_dp_mst_port *port;
 	int old_ddps = 0, ret;
 	u8 new_pdt = DP_PEER_DEVICE_NONE;
+	bool new_mcs = 0;
 	bool created = false, send_link_addr = false, changed = false;
 
 	port = drm_dp_get_port(mstb, port_msg->port_number);
@@ -2268,7 +2285,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
 	port->input = port_msg->input_port;
 	if (!port->input)
 		new_pdt = port_msg->peer_device_type;
-	port->mcs = port_msg->mcs;
+	new_mcs = port_msg->mcs;
 	port->ddps = port_msg->ddps;
 	port->ldps = port_msg->legacy_device_plug_status;
 	port->dpcd_rev = port_msg->dpcd_revision;
@@ -2296,7 +2313,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
 		}
 	}
 
-	ret = drm_dp_port_set_pdt(port, new_pdt);
+	ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
 	if (ret == 1) {
 		send_link_addr = true;
 	} else if (ret < 0) {
@@ -2310,7 +2327,8 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
 	 * we're coming out of suspend. In this case, always resend the link
 	 * address if there's an MSTB on this port
 	 */
-	if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING)
+	if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
+	    port->mcs)
 		send_link_addr = true;
 
 	if (port->connector)
@@ -2347,6 +2365,7 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
 	struct drm_dp_mst_port *port;
 	int old_ddps, old_input, ret, i;
 	u8 new_pdt;
+	bool new_mcs;
 	bool dowork = false, create_connector = false;
 
 	port = drm_dp_get_port(mstb, conn_stat->port_number);
@@ -2378,7 +2397,6 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
 	old_ddps = port->ddps;
 	old_input = port->input;
 	port->input = conn_stat->input_port;
-	port->mcs = conn_stat->message_capability_status;
 	port->ldps = conn_stat->legacy_device_plug_status;
 	port->ddps = conn_stat->displayport_device_plug_status;
 
@@ -2391,8 +2409,8 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
 	}
 
 	new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
-
-	ret = drm_dp_port_set_pdt(port, new_pdt);
+	new_mcs = conn_stat->message_capability_status;
+	ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
 	if (ret == 1) {
 		dowork = true;
 	} else if (ret < 0) {
@@ -2627,7 +2645,8 @@ static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
 	return false;
 }
 
-static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
+static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
+			    u8 port_num, u32 offset, u8 num_bytes)
 {
 	struct drm_dp_sideband_msg_req_body req;
 
@@ -2636,8 +2655,6 @@ static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32
 	req.u.dpcd_read.dpcd_address = offset;
 	req.u.dpcd_read.num_bytes = num_bytes;
 	drm_dp_encode_sideband_req(&req, msg);
-
-	return 0;
 }
 
 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
@@ -2863,7 +2880,7 @@ static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
 	struct drm_dp_sideband_msg_tx *txmsg;
 	struct drm_dp_link_address_ack_reply *reply;
 	struct drm_dp_mst_port *port, *tmp;
-	int i, len, ret, port_mask = 0;
+	int i, ret, port_mask = 0;
 	bool changed = false;
 
 	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
@@ -2871,7 +2888,7 @@ static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
 		return -ENOMEM;
 
 	txmsg->dst = mstb;
-	len = build_link_address(txmsg);
+	build_link_address(txmsg);
 
 	mstb->link_address_sent = true;
 	drm_dp_queue_down_tx(mgr, txmsg);
@@ -2892,7 +2909,15 @@ static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
 	DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
 	drm_dp_dump_link_address(reply);
 
-	drm_dp_check_mstb_guid(mstb, reply->guid);
+	ret = drm_dp_check_mstb_guid(mstb, reply->guid);
+	if (ret) {
+		char buf[64];
+
+		drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
+		DRM_ERROR("GUID check on %s failed: %d\n",
+			  buf, ret);
+		goto out;
+	}
 
 	for (i = 0; i < reply->nports; i++) {
 		port_mask |= BIT(reply->ports[i].port_number);
@@ -2933,14 +2958,14 @@ void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
 					struct drm_dp_mst_branch *mstb)
 {
 	struct drm_dp_sideband_msg_tx *txmsg;
-	int len, ret;
+	int ret;
 
 	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
 	if (!txmsg)
 		return;
 
 	txmsg->dst = mstb;
-	len = build_clear_payload_id_table(txmsg);
+	build_clear_payload_id_table(txmsg);
 
 	drm_dp_queue_down_tx(mgr, txmsg);
 
@@ -2958,7 +2983,6 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
 {
 	struct drm_dp_enum_path_resources_ack_reply *path_res;
 	struct drm_dp_sideband_msg_tx *txmsg;
-	int len;
 	int ret;
 
 	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
@@ -2966,7 +2990,7 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
 		return -ENOMEM;
 
 	txmsg->dst = mstb;
-	len = build_enum_path_resources(txmsg, port->port_num);
+	build_enum_path_resources(txmsg, port->port_num);
 
 	drm_dp_queue_down_tx(mgr, txmsg);
 
@@ -3050,7 +3074,7 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
 {
 	struct drm_dp_sideband_msg_tx *txmsg;
 	struct drm_dp_mst_branch *mstb;
-	int len, ret, port_num;
+	int ret, port_num;
 	u8 sinks[DRM_DP_MAX_SDP_STREAMS];
 	int i;
 
@@ -3075,9 +3099,9 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
 		sinks[i] = i;
 
 	txmsg->dst = mstb;
-	len = build_allocate_payload(txmsg, port_num,
-				     id,
-				     pbn, port->num_sdp_streams, sinks);
+	build_allocate_payload(txmsg, port_num,
+			       id,
+			       pbn, port->num_sdp_streams, sinks);
 
 	drm_dp_queue_down_tx(mgr, txmsg);
 
@@ -3106,7 +3130,7 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
 				 struct drm_dp_mst_port *port, bool power_up)
 {
 	struct drm_dp_sideband_msg_tx *txmsg;
-	int len, ret;
+	int ret;
 
 	port = drm_dp_mst_topology_get_port_validated(mgr, port);
 	if (!port)
@@ -3119,7 +3143,7 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
 	}
 
 	txmsg->dst = port->parent;
-	len = build_power_updown_phy(txmsg, port->port_num, power_up);
+	build_power_updown_phy(txmsg, port->port_num, power_up);
 	drm_dp_queue_down_tx(mgr, txmsg);
 
 	ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
@@ -3341,7 +3365,6 @@ static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
 				 struct drm_dp_mst_port *port,
 				 int offset, int size, u8 *bytes)
 {
-	int len;
 	int ret = 0;
 	struct drm_dp_sideband_msg_tx *txmsg;
 	struct drm_dp_mst_branch *mstb;
@@ -3356,7 +3379,7 @@ static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
 		goto fail_put;
 	}
 
-	len = build_dpcd_read(txmsg, port->port_num, offset, size);
+	build_dpcd_read(txmsg, port->port_num, offset, size);
 	txmsg->dst = port->parent;
 
 	drm_dp_queue_down_tx(mgr, txmsg);
@@ -3394,7 +3417,6 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
 				  struct drm_dp_mst_port *port,
 				  int offset, int size, u8 *bytes)
 {
-	int len;
 	int ret;
 	struct drm_dp_sideband_msg_tx *txmsg;
 	struct drm_dp_mst_branch *mstb;
@@ -3409,18 +3431,15 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
 		goto fail_put;
 	}
 
-	len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
+	build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
 	txmsg->dst = mstb;
 
 	drm_dp_queue_down_tx(mgr, txmsg);
 
 	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
-	if (ret > 0) {
-		if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
-			ret = -EIO;
-		else
-			ret = 0;
-	}
+	if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
+		ret = -EIO;
+
 	kfree(txmsg);
 fail_put:
 	drm_dp_mst_topology_put_mstb(mstb);
@@ -3481,9 +3500,9 @@ static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8  dp_link_count)
 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
 {
 	int ret = 0;
-	int i = 0;
 	struct drm_dp_mst_branch *mstb = NULL;
 
+	mutex_lock(&mgr->payload_lock);
 	mutex_lock(&mgr->lock);
 	if (mst_state == mgr->mst_state)
 		goto out_unlock;
@@ -3491,6 +3510,8 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 	mgr->mst_state = mst_state;
 	/* set the device into MST mode */
 	if (mst_state) {
+		struct drm_dp_payload reset_pay;
+
 		WARN_ON(mgr->mst_primary);
 
 		/* get dpcd info */
@@ -3520,17 +3541,15 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 		drm_dp_mst_topology_get_mstb(mgr->mst_primary);
 
 		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
-							 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
-		if (ret < 0) {
+					 DP_MST_EN |
+					 DP_UP_REQ_EN |
+					 DP_UPSTREAM_IS_SRC);
+		if (ret < 0)
 			goto out_unlock;
-		}
 
-		{
-			struct drm_dp_payload reset_pay;
-			reset_pay.start_slot = 0;
-			reset_pay.num_slots = 0x3f;
-			drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
-		}
+		reset_pay.start_slot = 0;
+		reset_pay.num_slots = 0x3f;
+		drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
 
 		queue_work(system_long_wq, &mgr->work);
 
@@ -3542,27 +3561,19 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 		/* this can fail if the device is gone */
 		drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
 		ret = 0;
-		mutex_lock(&mgr->payload_lock);
-		memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
+		memset(mgr->payloads, 0,
+		       mgr->max_payloads * sizeof(mgr->payloads[0]));
+		memset(mgr->proposed_vcpis, 0,
+		       mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
 		mgr->payload_mask = 0;
 		set_bit(0, &mgr->payload_mask);
-		for (i = 0; i < mgr->max_payloads; i++) {
-			struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
-
-			if (vcpi) {
-				vcpi->vcpi = 0;
-				vcpi->num_slots = 0;
-			}
-			mgr->proposed_vcpis[i] = NULL;
-		}
 		mgr->vcpi_mask = 0;
-		mutex_unlock(&mgr->payload_lock);
-
 		mgr->payload_id_table_cleared = false;
 	}
 
 out_unlock:
 	mutex_unlock(&mgr->lock);
+	mutex_unlock(&mgr->payload_lock);
 	if (mstb)
 		drm_dp_mst_topology_put_mstb(mstb);
 	return ret;
@@ -3663,7 +3674,12 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
 		DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
 		goto out_fail;
 	}
-	drm_dp_check_mstb_guid(mgr->mst_primary, guid);
+
+	ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
+	if (ret) {
+		DRM_DEBUG_KMS("check mstb failed - undocked during suspend?\n");
+		goto out_fail;
+	}
 
 	/*
 	 * For the final step of resuming the topology, we need to bring the
@@ -3690,7 +3706,7 @@ static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
 {
 	int len;
 	u8 replyblock[32];
-	int replylen, origlen, curreply;
+	int replylen, curreply;
 	int ret;
 	struct drm_dp_sideband_msg_rx *msg;
 	int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
@@ -3710,7 +3726,6 @@ static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
 	}
 	replylen = msg->curchunk_len + msg->curchunk_hdrlen;
 
-	origlen = replylen;
 	replylen -= len;
 	curreply = len;
 	while (replylen > 0) {
@@ -3820,7 +3835,8 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
 		else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
 			guid = msg->u.resource_stat.guid;
 
-		mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
+		if (guid)
+			mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
 	} else {
 		mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
 	}
@@ -4007,6 +4023,8 @@ drm_dp_mst_detect_port(struct drm_connector *connector,
 	switch (port->pdt) {
 	case DP_PEER_DEVICE_NONE:
 	case DP_PEER_DEVICE_MST_BRANCHING:
+		if (!port->mcs)
+			ret = connector_status_connected;
 		break;
 
 	case DP_PEER_DEVICE_SST_SINK:
@@ -4603,15 +4621,34 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
 		int ret;
 
 		ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
+		if (ret) {
+			seq_printf(m, "dpcd read failed\n");
+			goto out;
+		}
 		seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
+
 		ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
+		if (ret) {
+			seq_printf(m, "faux/mst read failed\n");
+			goto out;
+		}
 		seq_printf(m, "faux/mst: %*ph\n", 2, buf);
+
 		ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
+		if (ret) {
+			seq_printf(m, "mst ctrl read failed\n");
+			goto out;
+		}
 		seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
 
 		/* dump the standard OUI branch header */
 		ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
+		if (ret) {
+			seq_printf(m, "branch oui read failed\n");
+			goto out;
+		}
 		seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
+
 		for (i = 0x3; i < 0x8 && buf[i]; i++)
 			seq_printf(m, "%c", buf[i]);
 		seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
@@ -4620,6 +4657,7 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
 			seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
 	}
 
+out:
 	mutex_unlock(&mgr->lock);
 
 }
@@ -4635,13 +4673,25 @@ static void drm_dp_tx_work(struct work_struct *work)
 	mutex_unlock(&mgr->qlock);
 }
 
+static inline void drm_dp_destroy_connector(struct drm_dp_mst_port *port)
+{
+	if (!port->connector)
+		return;
+
+	if (port->mgr->cbs->destroy_connector) {
+		port->mgr->cbs->destroy_connector(port->mgr, port->connector);
+	} else {
+		drm_connector_unregister(port->connector);
+		drm_connector_put(port->connector);
+	}
+}
+
 static inline void
 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
 {
-	if (port->connector)
-		port->mgr->cbs->destroy_connector(port->mgr, port->connector);
+	drm_dp_destroy_connector(port);
 
-	drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE);
+	drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
 	drm_dp_mst_put_port_malloc(port);
 }
 
@@ -5440,7 +5490,8 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
 	if (drm_dp_read_desc(port->mgr->aux, &desc, true))
 		return NULL;
 
-	if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
+	if (drm_dp_has_quirk(&desc, 0,
+			     DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
 	    port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
 	    port->parent == port->mgr->mst_primary) {
 		u8 downstreamport;