diff options
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 28 | ||||
| -rw-r--r-- | include/drm/drm_dp_mst_helper.h | 32 |
2 files changed, 46 insertions, 14 deletions
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 1aaeeb884b9c..2f87dec31c3c 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2147,37 +2147,40 @@ static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *m struct drm_dp_mst_branch *mstb) { struct drm_dp_mst_port *port; - struct drm_dp_mst_branch *mstb_child; + if (!mstb->link_address_sent) drm_dp_send_link_address(mgr, mstb); list_for_each_entry(port, &mstb->ports, next) { - if (port->input) - continue; + struct drm_dp_mst_branch *mstb_child = NULL; - if (!port->ddps) + if (port->input || !port->ddps) continue; if (!port->available_pbn) drm_dp_send_enum_path_resources(mgr, mstb, port); - if (port->mstb) { + if (port->mstb) mstb_child = drm_dp_mst_topology_get_mstb_validated( mgr, port->mstb); - if (mstb_child) { - drm_dp_check_and_send_link_address(mgr, mstb_child); - drm_dp_mst_topology_put_mstb(mstb_child); - } + + if (mstb_child) { + drm_dp_check_and_send_link_address(mgr, mstb_child); + drm_dp_mst_topology_put_mstb(mstb_child); } } } static void drm_dp_mst_link_probe_work(struct work_struct *work) { - struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work); + struct drm_dp_mst_topology_mgr *mgr = + container_of(work, struct drm_dp_mst_topology_mgr, work); + struct drm_device *dev = mgr->dev; struct drm_dp_mst_branch *mstb; int ret; + mutex_lock(&mgr->probe_lock); + mutex_lock(&mgr->lock); mstb = mgr->mst_primary; if (mstb) { @@ -2190,6 +2193,7 @@ static void drm_dp_mst_link_probe_work(struct work_struct *work) drm_dp_check_and_send_link_address(mgr, mstb); drm_dp_mst_topology_put_mstb(mstb); } + mutex_unlock(&mgr->probe_lock); } static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, @@ -3313,6 +3317,7 @@ static void drm_dp_mst_up_req_work(struct work_struct *work) up_req_work); struct drm_dp_pending_up_req *up_req; + mutex_lock(&mgr->probe_lock); while (true) { mutex_lock(&mgr->up_req_lock); up_req = list_first_entry_or_null(&mgr->up_req_list, @@ -3328,6 +3333,7 @@ static void drm_dp_mst_up_req_work(struct work_struct *work) drm_dp_mst_process_up_req(mgr, up_req); kfree(up_req); } + mutex_unlock(&mgr->probe_lock); } static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) @@ -4352,6 +4358,7 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, mutex_init(&mgr->payload_lock); mutex_init(&mgr->delayed_destroy_lock); mutex_init(&mgr->up_req_lock); + mutex_init(&mgr->probe_lock); INIT_LIST_HEAD(&mgr->tx_msg_downq); INIT_LIST_HEAD(&mgr->destroy_port_list); INIT_LIST_HEAD(&mgr->destroy_branch_device_list); @@ -4417,6 +4424,7 @@ void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) mutex_destroy(&mgr->qlock); mutex_destroy(&mgr->lock); mutex_destroy(&mgr->up_req_lock); + mutex_destroy(&mgr->probe_lock); } EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h index 7d80c38ee00e..bccb5514e0ef 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -55,8 +55,6 @@ struct drm_dp_vcpi { * @num_sdp_stream_sinks: Number of stream sinks * @available_pbn: Available bandwidth for this port. * @next: link to next port on this branch device - * @mstb: branch device on this port, protected by - * &drm_dp_mst_topology_mgr.lock * @aux: i2c aux transport to talk to device connected to this port, protected * by &drm_dp_mst_topology_mgr.lock * @parent: branch device parent of this port @@ -92,7 +90,17 @@ struct drm_dp_mst_port { u8 num_sdp_stream_sinks; uint16_t available_pbn; struct list_head next; - struct drm_dp_mst_branch *mstb; /* pointer to an mstb if this port has one */ + /** + * @mstb: the branch device connected to this port, if there is one. + * This should be considered protected for reading by + * &drm_dp_mst_topology_mgr.lock. There are two exceptions to this: + * &drm_dp_mst_topology_mgr.up_req_work and + * &drm_dp_mst_topology_mgr.work, which do not grab + * &drm_dp_mst_topology_mgr.lock during reads but are the only + * updaters of this list and are protected from writing concurrently + * by &drm_dp_mst_topology_mgr.probe_lock. + */ + struct drm_dp_mst_branch *mstb; struct drm_dp_aux aux; /* i2c bus for this port? */ struct drm_dp_mst_branch *parent; @@ -118,7 +126,6 @@ struct drm_dp_mst_port { * @lct: Link count total to talk to this branch device. * @num_ports: number of ports on the branch. * @msg_slots: one bit per transmitted msg slot. - * @ports: linked list of ports on this branch. * @port_parent: pointer to the port parent, NULL if toplevel. * @mgr: topology manager for this branch device. * @tx_slots: transmission slots for this device. @@ -156,6 +163,16 @@ struct drm_dp_mst_branch { int num_ports; int msg_slots; + /** + * @ports: the list of ports on this branch device. This should be + * considered protected for reading by &drm_dp_mst_topology_mgr.lock. + * There are two exceptions to this: + * &drm_dp_mst_topology_mgr.up_req_work and + * &drm_dp_mst_topology_mgr.work, which do not grab + * &drm_dp_mst_topology_mgr.lock during reads but are the only + * updaters of this list and are protected from updating the list + * concurrently by @drm_dp_mst_topology_mgr.probe_lock + */ struct list_head ports; /* list of tx ops queue for this port */ @@ -503,6 +520,13 @@ struct drm_dp_mst_topology_mgr { struct mutex lock; /** + * @probe_lock: Prevents @work and @up_req_work, the only writers of + * &drm_dp_mst_port.mstb and &drm_dp_mst_branch.ports, from racing + * while they update the topology. + */ + struct mutex probe_lock; + + /** * @mst_state: If this manager is enabled for an MST capable port. False * if no MST sink/branch devices is connected. */ |