Bluetooth: hci_sync: Rework hci_suspend_notifier

This makes hci_suspend_notifier use the hci_*_sync which can be
executed synchronously which is allowed in the suspend_notifier and
simplifies a lot of the handling since the status of each command can
be checked inline so no other work need to be scheduled thus can be
performed without using of a state machine.

Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Signed-off-by: Marcel Holtmann <[email protected]>

Author: Vudentz

include/net/bluetooth/hci_core.h

@@ -523,7 +523,6 @@ struct hci_dev {
 	bool			advertising_paused;
 
 	struct notifier_block	suspend_notifier;
-	struct work_struct	suspend_prepare;
 	enum suspended_state	suspend_state_next;
 	enum suspended_state	suspend_state;
 	bool			scanning_paused;
@@ -532,9 +531,6 @@ struct hci_dev {
 	bdaddr_t		wake_addr;
 	u8			wake_addr_type;
 
-	wait_queue_head_t	suspend_wait_q;
-	DECLARE_BITMAP(suspend_tasks, __SUSPEND_NUM_TASKS);
-
 	struct hci_conn_hash	conn_hash;
 
 	struct list_head	mgmt_pending;

include/net/bluetooth/hci_sync.h

@@ -92,3 +92,6 @@ int hci_set_powered_sync(struct hci_dev *hdev, u8 val);
 
 int hci_start_discovery_sync(struct hci_dev *hdev);
 int hci_stop_discovery_sync(struct hci_dev *hdev);
+
+int hci_suspend_sync(struct hci_dev *hdev);
+int hci_resume_sync(struct hci_dev *hdev);

net/bluetooth/hci_conn.c

@@ -900,16 +900,6 @@ void hci_le_conn_failed(struct hci_conn *conn, u8 status)
 
 	hci_conn_del(conn);
 
-	/* The suspend notifier is waiting for all devices to disconnect and an
-	 * LE connect cancel will result in an hci_le_conn_failed. Once the last
-	 * connection is deleted, we should also wake the suspend queue to
-	 * complete suspend operations.
-	 */
-	if (list_empty(&hdev->conn_hash.list) &&
-	    test_and_clear_bit(SUSPEND_DISCONNECTING, hdev->suspend_tasks)) {
-		wake_up(&hdev->suspend_wait_q);
-	}
-
 	/* Since we may have temporarily stopped the background scanning in
 	 * favor of connection establishment, we should restart it.
 	 */

net/bluetooth/hci_core.c

@@ -2374,61 +2374,6 @@ void hci_copy_identity_address(struct hci_dev *hdev, bdaddr_t *bdaddr,
 	}
 }
 
-static void hci_suspend_clear_tasks(struct hci_dev *hdev)
-{
-	int i;
-
-	for (i = 0; i < __SUSPEND_NUM_TASKS; i++)
-		clear_bit(i, hdev->suspend_tasks);
-
-	wake_up(&hdev->suspend_wait_q);
-}
-
-static int hci_suspend_wait_event(struct hci_dev *hdev)
-{
-#define WAKE_COND                                                              \
-	(find_first_bit(hdev->suspend_tasks, __SUSPEND_NUM_TASKS) ==           \
-	 __SUSPEND_NUM_TASKS)
-
-	int i;
-	int ret = wait_event_timeout(hdev->suspend_wait_q,
-				     WAKE_COND, SUSPEND_NOTIFIER_TIMEOUT);
-
-	if (ret == 0) {
-		bt_dev_err(hdev, "Timed out waiting for suspend events");
-		for (i = 0; i < __SUSPEND_NUM_TASKS; ++i) {
-			if (test_bit(i, hdev->suspend_tasks))
-				bt_dev_err(hdev, "Suspend timeout bit: %d", i);
-			clear_bit(i, hdev->suspend_tasks);
-		}
-
-		ret = -ETIMEDOUT;
-	} else {
-		ret = 0;
-	}
-
-	return ret;
-}
-
-static void hci_prepare_suspend(struct work_struct *work)
-{
-	struct hci_dev *hdev =
-		container_of(work, struct hci_dev, suspend_prepare);
-
-	hci_dev_lock(hdev);
-	hci_req_prepare_suspend(hdev, hdev->suspend_state_next);
-	hci_dev_unlock(hdev);
-}
-
-static int hci_change_suspend_state(struct hci_dev *hdev,
-				    enum suspended_state next)
-{
-	hdev->suspend_state_next = next;
-	set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
-	queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
-	return hci_suspend_wait_event(hdev);
-}
-
 static void hci_clear_wake_reason(struct hci_dev *hdev)
 {
 	hci_dev_lock(hdev);
@@ -2565,7 +2510,6 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv)
 	INIT_WORK(&hdev->tx_work, hci_tx_work);
 	INIT_WORK(&hdev->power_on, hci_power_on);
 	INIT_WORK(&hdev->error_reset, hci_error_reset);
-	INIT_WORK(&hdev->suspend_prepare, hci_prepare_suspend);
 
 	hci_cmd_sync_init(hdev);
 
@@ -2576,7 +2520,6 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv)
 	skb_queue_head_init(&hdev->raw_q);
 
 	init_waitqueue_head(&hdev->req_wait_q);
-	init_waitqueue_head(&hdev->suspend_wait_q);
 
 	INIT_DELAYED_WORK(&hdev->cmd_timer, hci_cmd_timeout);
 	INIT_DELAYED_WORK(&hdev->ncmd_timer, hci_ncmd_timeout);
@@ -2729,11 +2672,8 @@ void hci_unregister_dev(struct hci_dev *hdev)
 
 	hci_cmd_sync_clear(hdev);
 
-	if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks)) {
-		hci_suspend_clear_tasks(hdev);
+	if (!test_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks))
 		unregister_pm_notifier(&hdev->suspend_notifier);
-		cancel_work_sync(&hdev->suspend_prepare);
-	}
 
 	msft_unregister(hdev);
 
@@ -2800,7 +2740,6 @@ EXPORT_SYMBOL(hci_release_dev);
 int hci_suspend_dev(struct hci_dev *hdev)
 {
 	int ret;
-	u8 state = BT_RUNNING;
 
 	bt_dev_dbg(hdev, "");
 
@@ -2809,40 +2748,17 @@ int hci_suspend_dev(struct hci_dev *hdev)
 	    hci_dev_test_flag(hdev, HCI_UNREGISTER))
 		return 0;
 
-	/* If powering down, wait for completion. */
-	if (mgmt_powering_down(hdev)) {
-		set_bit(SUSPEND_POWERING_DOWN, hdev->suspend_tasks);
-		ret = hci_suspend_wait_event(hdev);
-		if (ret)
-			goto done;
-	}
-
-	/* Suspend consists of two actions:
-	 *  - First, disconnect everything and make the controller not
-	 *    connectable (disabling scanning)
-	 *  - Second, program event filter/accept list and enable scan
-	 */
-	ret = hci_change_suspend_state(hdev, BT_SUSPEND_DISCONNECT);
-	if (ret)
-		goto clear;
-
-	state = BT_SUSPEND_DISCONNECT;
+	/* If powering down don't attempt to suspend */
+	if (mgmt_powering_down(hdev))
+		return 0;
 
-	/* Only configure accept list if device may wakeup. */
-	if (hdev->wakeup && hdev->wakeup(hdev)) {
-		ret = hci_change_suspend_state(hdev, BT_SUSPEND_CONFIGURE_WAKE);
-		if (!ret)
-			state = BT_SUSPEND_CONFIGURE_WAKE;
-	}
+	hci_req_sync_lock(hdev);
+	ret = hci_suspend_sync(hdev);
+	hci_req_sync_unlock(hdev);
 
-clear:
 	hci_clear_wake_reason(hdev);
-	mgmt_suspending(hdev, state);
+	mgmt_suspending(hdev, hdev->suspend_state);
 
-done:
-	/* We always allow suspend even if suspend preparation failed and
-	 * attempt to recover in resume.
-	 */
 	hci_sock_dev_event(hdev, HCI_DEV_SUSPEND);
 	return ret;
 }
@@ -2864,10 +2780,12 @@ int hci_resume_dev(struct hci_dev *hdev)
 	if (mgmt_powering_down(hdev))
 		return 0;
 
-	ret = hci_change_suspend_state(hdev, BT_RUNNING);
+	hci_req_sync_lock(hdev);
+	ret = hci_resume_sync(hdev);
+	hci_req_sync_unlock(hdev);
 
 	mgmt_resuming(hdev, hdev->wake_reason, &hdev->wake_addr,
-			      hdev->wake_addr_type);
+		      hdev->wake_addr_type);
 
 	hci_sock_dev_event(hdev, HCI_DEV_RESUME);
 	return ret;

net/bluetooth/hci_event.c

@@ -2414,9 +2414,14 @@ static void hci_cs_exit_sniff_mode(struct hci_dev *hdev, __u8 status)
 static void hci_cs_disconnect(struct hci_dev *hdev, u8 status)
 {
 	struct hci_cp_disconnect *cp;
+	struct hci_conn_params *params;
 	struct hci_conn *conn;
+	bool mgmt_conn;
 
-	if (!status)
+	/* Wait for HCI_EV_DISCONN_COMPLETE if status 0x00 and not suspended
+	 * otherwise cleanup the connection immediately.
+	 */
+	if (!status && !hdev->suspended)
 		return;
 
 	cp = hci_sent_cmd_data(hdev, HCI_OP_DISCONNECT);
@@ -2426,7 +2431,10 @@ static void hci_cs_disconnect(struct hci_dev *hdev, u8 status)
 	hci_dev_lock(hdev);
 
 	conn = hci_conn_hash_lookup_handle(hdev, __le16_to_cpu(cp->handle));
-	if (conn) {
+	if (!conn)
+		goto unlock;
+
+	if (status) {
 		mgmt_disconnect_failed(hdev, &conn->dst, conn->type,
 				       conn->dst_type, status);
 
@@ -2435,14 +2443,48 @@ static void hci_cs_disconnect(struct hci_dev *hdev, u8 status)
 			hci_enable_advertising(hdev);
 		}
 
-		/* If the disconnection failed for any reason, the upper layer
-		 * does not retry to disconnect in current implementation.
-		 * Hence, we need to do some basic cleanup here and re-enable
-		 * advertising if necessary.
-		 */
-		hci_conn_del(conn);
+		goto done;
 	}
 
+	mgmt_conn = test_and_clear_bit(HCI_CONN_MGMT_CONNECTED, &conn->flags);
+
+	if (conn->type == ACL_LINK) {
+		if (test_bit(HCI_CONN_FLUSH_KEY, &conn->flags))
+			hci_remove_link_key(hdev, &conn->dst);
+	}
+
+	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
+	if (params) {
+		switch (params->auto_connect) {
+		case HCI_AUTO_CONN_LINK_LOSS:
+			if (cp->reason != HCI_ERROR_CONNECTION_TIMEOUT)
+				break;
+			fallthrough;
+
+		case HCI_AUTO_CONN_DIRECT:
+		case HCI_AUTO_CONN_ALWAYS:
+			list_del_init(&params->action);
+			list_add(&params->action, &hdev->pend_le_conns);
+			break;
+
+		default:
+			break;
+		}
+	}
+
+	mgmt_device_disconnected(hdev, &conn->dst, conn->type, conn->dst_type,
+				 cp->reason, mgmt_conn);
+
+	hci_disconn_cfm(conn, cp->reason);
+
+done:
+	/* If the disconnection failed for any reason, the upper layer
+	 * does not retry to disconnect in current implementation.
+	 * Hence, we need to do some basic cleanup here and re-enable
+	 * advertising if necessary.
+	 */
+	hci_conn_del(conn);
+unlock:
 	hci_dev_unlock(hdev);
 }
 
@@ -3047,14 +3089,6 @@ static void hci_disconn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 
 	hci_conn_del(conn);
 
-	/* The suspend notifier is waiting for all devices to disconnect so
-	 * clear the bit from pending tasks and inform the wait queue.
-	 */
-	if (list_empty(&hdev->conn_hash.list) &&
-	    test_and_clear_bit(SUSPEND_DISCONNECTING, hdev->suspend_tasks)) {
-		wake_up(&hdev->suspend_wait_q);
-	}
-
 unlock:
 	hci_dev_unlock(hdev);
 }
@@ -5575,8 +5609,9 @@ static struct hci_conn *check_pending_le_conn(struct hci_dev *hdev,
 	if (adv_type != LE_ADV_IND && adv_type != LE_ADV_DIRECT_IND)
 		return NULL;
 
-	/* Ignore if the device is blocked */
-	if (hci_bdaddr_list_lookup(&hdev->reject_list, addr, addr_type))
+	/* Ignore if the device is blocked or hdev is suspended */
+	if (hci_bdaddr_list_lookup(&hdev->reject_list, addr, addr_type) ||
+	    hdev->suspended)
 		return NULL;
 
 	/* Most controller will fail if we try to create new connections