We want to start cutting down on all of the places that we use port validation, so that ports may be removed from the topology as quickly as possible to minimize the number of errors we run into as a result of being out of sync with the current topology status. This isn't a very typical scenario and I don't think I've ever even run into it - but since the next commit is going to make some changes to payload updates depending on their hotplug status I think it's a probably good idea to take precautions.
Let's do this with CSNs by moving some code around so that we only queue link address probing work at the end of handling all CSNs - allowing us to make sure we drop as many topology references as we can beforehand.
Signed-off-by: Lyude Paul lyude@redhat.com Cc: Wayne Lin Wayne.Lin@amd.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Fangzhi Zuo Jerry.Zuo@amd.com Cc: Jani Nikula jani.nikula@intel.com Cc: Imre Deak imre.deak@intel.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sean Paul sean@poorly.run --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index a775f9437868..dd314586bac3 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -2508,7 +2508,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, return ret; }
-static void +static int drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, struct drm_dp_connection_status_notify *conn_stat) { @@ -2521,7 +2521,7 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
port = drm_dp_get_port(mstb, conn_stat->port_number); if (!port) - return; + return 0;
if (port->connector) { if (!port->input && conn_stat->input_port) { @@ -2574,8 +2574,7 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
out: drm_dp_mst_topology_put_port(port); - if (dowork) - queue_work(system_long_wq, &mstb->mgr->work); + return dowork; }
static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, @@ -4071,7 +4070,7 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb = NULL; struct drm_dp_sideband_msg_req_body *msg = &up_req->msg; struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr; - bool hotplug = false; + bool hotplug = false, dowork = false;
if (hdr->broadcast) { const u8 *guid = NULL; @@ -4094,11 +4093,14 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
/* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */ if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { - drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); + dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); hotplug = true; }
drm_dp_mst_topology_put_mstb(mstb); + + if (dowork) + queue_work(system_long_wq, &mgr->work); return hotplug; }