drm/dp/mst: move GUID storage from mgr, port to only mst branch

commit 5e93b8208d3c419b515fb75e2601931c027e12ab upstream.

Previous implementation does not handle case below: boot up one MST branch
to DP connector of ASIC. After boot up, hot plug 2nd MST branch to DP output
of 1st MST, GUID is not created for 2nd MST branch. When downstream port of
2nd MST branch send upstream request, it fails because 2nd MST branch GUID
is not available.

New Implementation: only create GUID for MST branch and save it within Branch.

Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 28 insertions, 36 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index e77e96aeeb20..c79e44a712e7 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1013,18 +1013,27 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
 	return send_link;
 }
 
-static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
-				   struct drm_dp_mst_port *port)
+static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
 {
 	int ret;
-	if (port->dpcd_rev >= 0x12) {
-		port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
-		if (!port->guid_valid) {
-			ret = drm_dp_send_dpcd_write(mstb->mgr,
-						     port,
-						     DP_GUID,
-						     16, port->guid);
-			port->guid_valid = true;
+
+	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);
+		} else {
+
+			ret = drm_dp_dpcd_write(
+					mstb->mgr->aux,
+					DP_GUID,
+					mstb->guid,
+					16);
 		}
 	}
 }
@@ -1081,7 +1090,6 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
 	port->dpcd_rev = port_msg->dpcd_revision;
 	port->num_sdp_streams = port_msg->num_sdp_streams;
 	port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
-	memcpy(port->guid, port_msg->peer_guid, 16);
 
 	/* manage mstb port lists with mgr lock - take a reference
 	   for this list */
@@ -1094,11 +1102,9 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
 
 	if (old_ddps != port->ddps) {
 		if (port->ddps) {
-			drm_dp_check_port_guid(mstb, port);
 			if (!port->input)
 				drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
 		} else {
-			port->guid_valid = false;
 			port->available_pbn = 0;
 			}
 	}
@@ -1157,10 +1163,8 @@ static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
 
 	if (old_ddps != port->ddps) {
 		if (port->ddps) {
-			drm_dp_check_port_guid(mstb, port);
 			dowork = true;
 		} else {
-			port->guid_valid = false;
 			port->available_pbn = 0;
 		}
 	}
@@ -1217,13 +1221,14 @@ static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
 	struct drm_dp_mst_branch *found_mstb;
 	struct drm_dp_mst_port *port;
 
+	if (memcmp(mstb->guid, guid, 16) == 0)
+		return mstb;
+
+
 	list_for_each_entry(port, &mstb->ports, next) {
 		if (!port->mstb)
 			continue;
 
-		if (port->guid_valid && memcmp(port->guid, guid, 16) == 0)
-			return port->mstb;
-
 		found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
 
 		if (found_mstb)
@@ -1242,10 +1247,7 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
 	/* find the port by iterating down */
 	mutex_lock(&mgr->lock);
 
-	if (mgr->guid_valid && memcmp(mgr->guid, guid, 16) == 0)
-		mstb = mgr->mst_primary;
-	else
-		mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
+	mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
 
 	if (mstb)
 		kref_get(&mstb->kref);
@@ -1550,6 +1552,9 @@ static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
 				       txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
 				       txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
 			}
+
+			drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
+
 			for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
 				drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
 			}
@@ -1984,20 +1989,6 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 			goto out_unlock;
 		}
 
-
-		/* sort out guid */
-		ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
-		if (ret != 16) {
-			DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
-			goto out_unlock;
-		}
-
-		mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
-		if (!mgr->guid_valid) {
-			ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
-			mgr->guid_valid = true;
-		}
-
 		queue_work(system_long_wq, &mgr->work);
 
 		ret = 0;
@@ -2219,6 +2210,7 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 			}
 
 			drm_dp_update_port(mstb, &msg.u.conn_stat);
+
 			DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
 			(*mgr->cbs->hotplug)(mgr);