Bluetooth: Fix Advertisement Monitor Suspend/Resume

During system suspend, advertisement monitoring is disabled by setting
the HCI_VS_MSFT_LE_Set_Advertisement_Filter_Enable to False. This
disables the monitoring during suspend, however, if the controller is
monitoring a device, it sends HCI_VS_MSFT_LE_Monitor_Device_Event to
indicate that the monitoring has been stopped for that particular
device. This event may occur after suspend depending on the
low_threshold_timeout and peer device advertisement frequency, which
causes early wake up.

Right way to disable the monitoring for suspend is by removing all the
monitors before suspend and re-monitor after resume to ensure no events
are received during suspend. This patch fixes this suspend/resume issue.

Following tests are performed:
- Add monitors before suspend and make sure DeviceFound gets triggered
- Suspend the system and verify that all monitors are removed by kernel
  but not Released by bluetoothd
- Wake up and verify that all monitors are added again and DeviceFound
  gets triggered

Signed-off-by: Manish Mandlik <mmandlik@google.com>
Reviewed-by: Archie Pusaka <apusaka@google.com>
Reviewed-by: Miao-chen Chou <mcchou@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 9 insertions, 6 deletions

diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 55885c4651ab..92611bfc0b9e 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -1105,21 +1105,24 @@ static void suspend_req_complete(struct hci_dev *hdev, u8 status, u16 opcode)
 	}
 }
 
-static void hci_req_add_set_adv_filter_enable(struct hci_request *req,
-					      bool enable)
+static void hci_req_prepare_adv_monitor_suspend(struct hci_request *req,
+						bool suspending)
 {
 	struct hci_dev *hdev = req->hdev;
 
 	switch (hci_get_adv_monitor_offload_ext(hdev)) {
 	case HCI_ADV_MONITOR_EXT_MSFT:
-		msft_req_add_set_filter_enable(req, enable);
+		if (suspending)
+			msft_suspend(hdev);
+		else
+			msft_resume(hdev);
 		break;
 	default:
 		return;
 	}
 
 	/* No need to block when enabling since it's on resume path */
-	if (hdev->suspended && !enable)
+	if (hdev->suspended && suspending)
 		set_bit(SUSPEND_SET_ADV_FILTER, hdev->suspend_tasks);
 }
 
@@ -1186,7 +1189,7 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		}
 
 		/* Disable advertisement filters */
-		hci_req_add_set_adv_filter_enable(&req, false);
+		hci_req_prepare_adv_monitor_suspend(&req, true);
 
 		/* Prevent disconnects from causing scanning to be re-enabled */
 		hdev->scanning_paused = true;
@@ -1228,7 +1231,7 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		/* Reset passive/background scanning to normal */
 		__hci_update_background_scan(&req);
 		/* Enable all of the advertisement filters */
-		hci_req_add_set_adv_filter_enable(&req, true);
+		hci_req_prepare_adv_monitor_suspend(&req, false);
 
 		/* Unpause directed advertising */
 		hdev->advertising_paused = false;