This will allow us to add some locking for port->* members, in particular the PDT and ->connector, which can't be done from drm_dp_destroy_port() since we don't know what locks the caller might be holding.
Note that we already do this in delayed_destroy_work (renamed from destroy_connector_work in this patch) for ports, we're just making it so mstbs are also destroyed in this worker.
Changes since v2: * Clarify commit message Changes since v4: * Clarify commit message more
Cc: Juston Li juston.li@intel.com Cc: Imre Deak imre.deak@intel.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Harry Wentland hwentlan@amd.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Reviewed-by: Sean Paul sean@poorly.run Signed-off-by: Lyude Paul lyude@redhat.com --- drivers/gpu/drm/drm_dp_mst_topology.c | 40 +++++++++++---------------- 1 file changed, 16 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 66ff226d8c86..204d0c832c65 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1510,31 +1510,22 @@ static void drm_dp_destroy_port(struct kref *kref) container_of(kref, struct drm_dp_mst_port, topology_kref); struct drm_dp_mst_topology_mgr *mgr = port->mgr;
- if (!port->input) { - kfree(port->cached_edid); + /* There's nothing that needs locking to destroy an input port yet */ + if (port->input) { + drm_dp_mst_put_port_malloc(port); + return; + }
- /* - * The only time we don't have a connector - * on an output port is if the connector init - * fails. - */ - if (port->connector) { - /* we can't destroy the connector here, as - * we might be holding the mode_config.mutex - * from an EDID retrieval */ + kfree(port->cached_edid);
- mutex_lock(&mgr->delayed_destroy_lock); - list_add(&port->next, &mgr->destroy_port_list); - mutex_unlock(&mgr->delayed_destroy_lock); - schedule_work(&mgr->delayed_destroy_work); - return; - } - /* no need to clean up vcpi - * as if we have no connector we never setup a vcpi */ - drm_dp_port_teardown_pdt(port, port->pdt); - port->pdt = DP_PEER_DEVICE_NONE; - } - drm_dp_mst_put_port_malloc(port); + /* + * we can't destroy the connector here, as we might be holding the + * mode_config.mutex from an EDID retrieval + */ + mutex_lock(&mgr->delayed_destroy_lock); + list_add(&port->next, &mgr->destroy_port_list); + mutex_unlock(&mgr->delayed_destroy_lock); + schedule_work(&mgr->delayed_destroy_work); }
/** @@ -3981,7 +3972,8 @@ static void drm_dp_tx_work(struct work_struct *work) static inline void drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) { - port->mgr->cbs->destroy_connector(port->mgr, port->connector); + if (port->connector) + port->mgr->cbs->destroy_connector(port->mgr, port->connector);
drm_dp_port_teardown_pdt(port, port->pdt); port->pdt = DP_PEER_DEVICE_NONE;