Bluetooth: pause/resume advertising around suspend

Currently, the controller will continue advertising when the system
enters suspend. This patch makes sure that all advertising instances are
paused when entering suspend, and resumed when suspend exits.

The Advertising and Suspend/Resume test suites were both run on this
change on 4.19 kernel with both hardware offloaded multi-advertising and
software rotated multi-advertising. In addition, a new test was added
that performs the following steps:
* Register 3 advertisements via bluez RegisterAdvertisement
* Verify reception of all advertisements by remote peer
* Enter suspend on DUT
* Verify failure to receive all advertisements by remote peer
* Exit suspend on DUT
* Verify reception of all advertisements by remote peer

Signed-off-by: Daniel Winkler <danielwinkler@google.com>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_request.c

@@ -1111,6 +1111,53 @@ static void hci_req_config_le_suspend_scan(struct hci_request *req)
 	set_bit(SUSPEND_SCAN_ENABLE, req->hdev->suspend_tasks);
 }
 
+static void cancel_adv_timeout(struct hci_dev *hdev)
+{
+	if (hdev->adv_instance_timeout) {
+		hdev->adv_instance_timeout = 0;
+		cancel_delayed_work(&hdev->adv_instance_expire);
+	}
+}
+
+/* This function requires the caller holds hdev->lock */
+static void hci_suspend_adv_instances(struct hci_request *req)
+{
+	bt_dev_dbg(req->hdev, "Suspending advertising instances");
+
+	/* Call to disable any advertisements active on the controller.
+	 * This will succeed even if no advertisements are configured.
+	 */
+	__hci_req_disable_advertising(req);
+
+	/* If we are using software rotation, pause the loop */
+	if (!ext_adv_capable(req->hdev))
+		cancel_adv_timeout(req->hdev);
+}
+
+/* This function requires the caller holds hdev->lock */
+static void hci_resume_adv_instances(struct hci_request *req)
+{
+	struct adv_info *adv;
+
+	bt_dev_dbg(req->hdev, "Resuming advertising instances");
+
+	if (ext_adv_capable(req->hdev)) {
+		/* Call for each tracked instance to be re-enabled */
+		list_for_each_entry(adv, &req->hdev->adv_instances, list) {
+			__hci_req_enable_ext_advertising(req,
+							 adv->instance);
+		}
+
+	} else {
+		/* Schedule for most recent instance to be restarted and begin
+		 * the software rotation loop
+		 */
+		__hci_req_schedule_adv_instance(req,
+						req->hdev->cur_adv_instance,
+						true);
+	}
+}
+
 static void suspend_req_complete(struct hci_dev *hdev, u8 status, u16 opcode)
 {
 	bt_dev_dbg(hdev, "Request complete opcode=0x%x, status=0x%x", opcode,
@@ -1153,7 +1200,7 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		hdev->discovery_paused = true;
 		hdev->discovery_old_state = old_state;
 
-		/* Stop advertising */
+		/* Stop directed advertising */
 		old_state = hci_dev_test_flag(hdev, HCI_ADVERTISING);
 		if (old_state) {
 			set_bit(SUSPEND_PAUSE_ADVERTISING, hdev->suspend_tasks);
@@ -1162,6 +1209,10 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 					   &hdev->discov_off, 0);
 		}
 
+		/* Pause other advertisements */
+		if (hdev->adv_instance_cnt)
+			hci_suspend_adv_instances(&req);
+
 		hdev->advertising_paused = true;
 		hdev->advertising_old_state = old_state;
 		/* Disable page scan */
@@ -1212,7 +1263,7 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		/* Reset passive/background scanning to normal */
 		hci_req_config_le_suspend_scan(&req);
 
-		/* Unpause advertising */
+		/* Unpause directed advertising */
 		hdev->advertising_paused = false;
 		if (hdev->advertising_old_state) {
 			set_bit(SUSPEND_UNPAUSE_ADVERTISING,
@@ -1223,6 +1274,10 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 			hdev->advertising_old_state = 0;
 		}
 
+		/* Resume other advertisements */
+		if (hdev->adv_instance_cnt)
+			hci_resume_adv_instances(&req);
+
 		/* Unpause discovery */
 		hdev->discovery_paused = false;
 		if (hdev->discovery_old_state != DISCOVERY_STOPPED &&
@@ -2186,14 +2241,6 @@ int __hci_req_schedule_adv_instance(struct hci_request *req, u8 instance,
 	return 0;
 }
 
-static void cancel_adv_timeout(struct hci_dev *hdev)
-{
-	if (hdev->adv_instance_timeout) {
-		hdev->adv_instance_timeout = 0;
-		cancel_delayed_work(&hdev->adv_instance_expire);
-	}
-}
-
 /* For a single instance:
  * - force == true: The instance will be removed even when its remaining
  *   lifetime is not zero.