This field on drm_dp_mst_branch was never filled It is initialized to zero when the port is kzallocced. When a port is added to the list, increment num_ports, and when a port is removed from the list, decrement num_ports. v2: remember to decrement on port removal v3: don't explicitly init to 0 Signed-off-by: David Francis <David.Francis@xxxxxxx> Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx> --- drivers/gpu/drm/drm_dp_mst_topology.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 11b02f6b9e8a..a39e42c7d868 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1669,6 +1669,7 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, mutex_lock(&mstb->mgr->lock); drm_dp_mst_topology_get_port(port); list_add(&port->next, &mstb->ports); + mstb->num_ports++; mutex_unlock(&mstb->mgr->lock); } @@ -1703,6 +1704,7 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb, /* remove it from the port list */ mutex_lock(&mstb->mgr->lock); list_del(&port->next); + mstb->num_ports--; mutex_unlock(&mstb->mgr->lock); /* drop port list reference */ drm_dp_mst_topology_put_port(port); -- 2.17.1 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel