[PATCH v2] bluetooth: Fix Advertisement Monitor Suspend/Resume
From: Manish Mandlik
Date: Tue Sep 21 2021 - 11:57:58 EST
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@xxxxxxxxxx>
Reviewed-by: Archie Pusaka <apusaka@xxxxxxxxxx>
Reviewed-by: Miao-chen Chou <mcchou@xxxxxxxxxx>
---
Changes in v2:
- Updated the Reviewd-by names
net/bluetooth/hci_request.c | 15 +++--
net/bluetooth/msft.c | 117 +++++++++++++++++++++++++++++++-----
net/bluetooth/msft.h | 5 ++
3 files changed, 116 insertions(+), 21 deletions(-)
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 47fb665277d4..c018a172ced3 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -1281,21 +1281,24 @@ 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_remove_all_monitors_on_suspend(hdev);
+ else
+ msft_reregister_monitors_on_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);
}
@@ -1362,7 +1365,7 @@ 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;
@@ -1404,7 +1407,7 @@ 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;
diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
index 21b1787e7893..328d5e341f9a 100644
--- a/net/bluetooth/msft.c
+++ b/net/bluetooth/msft.c
@@ -94,11 +94,14 @@ struct msft_data {
__u16 pending_add_handle;
__u16 pending_remove_handle;
__u8 reregistering;
+ __u8 suspending;
__u8 filter_enabled;
};
static int __msft_add_monitor_pattern(struct hci_dev *hdev,
struct adv_monitor *monitor);
+static int __msft_remove_monitor(struct hci_dev *hdev,
+ struct adv_monitor *monitor, u16 handle);
bool msft_monitor_supported(struct hci_dev *hdev)
{
@@ -154,7 +157,7 @@ static bool read_supported_features(struct hci_dev *hdev,
}
/* This function requires the caller holds hdev->lock */
-static void reregister_monitor_on_restart(struct hci_dev *hdev, int handle)
+static void reregister_monitor(struct hci_dev *hdev, int handle)
{
struct adv_monitor *monitor;
struct msft_data *msft = hdev->msft_data;
@@ -182,6 +185,69 @@ static void reregister_monitor_on_restart(struct hci_dev *hdev, int handle)
}
}
+/* This function requires the caller holds hdev->lock */
+static void remove_monitor_on_suspend(struct hci_dev *hdev, int handle)
+{
+ struct adv_monitor *monitor;
+ struct msft_data *msft = hdev->msft_data;
+ int err;
+
+ while (1) {
+ monitor = idr_get_next(&hdev->adv_monitors_idr, &handle);
+ if (!monitor) {
+ /* All monitors have been removed */
+ msft->suspending = false;
+ hci_update_background_scan(hdev);
+ return;
+ }
+
+ msft->pending_remove_handle = (u16)handle;
+ err = __msft_remove_monitor(hdev, monitor, handle);
+
+ /* If success, return and wait for monitor removed callback */
+ if (!err)
+ return;
+
+ /* Otherwise free the monitor and keep removing */
+ hci_free_adv_monitor(hdev, monitor);
+ handle++;
+ }
+}
+
+/* This function requires the caller holds hdev->lock */
+void msft_remove_all_monitors_on_suspend(struct hci_dev *hdev)
+{
+ struct msft_data *msft = hdev->msft_data;
+
+ if (!msft)
+ return;
+
+ if (msft_monitor_supported(hdev)) {
+ msft->suspending = true;
+ /* Quitely remove all monitors on suspend to avoid waking up
+ * the system.
+ */
+ remove_monitor_on_suspend(hdev, 0);
+ }
+}
+
+/* This function requires the caller holds hdev->lock */
+void msft_reregister_monitors_on_resume(struct hci_dev *hdev)
+{
+ struct msft_data *msft = hdev->msft_data;
+
+ if (!msft)
+ return;
+
+ if (msft_monitor_supported(hdev)) {
+ msft->reregistering = true;
+ /* Monitors are removed on suspend, so we need to add all
+ * monitors on resume.
+ */
+ reregister_monitor(hdev, 0);
+ }
+}
+
void msft_do_open(struct hci_dev *hdev)
{
struct msft_data *msft = hdev->msft_data;
@@ -214,7 +280,7 @@ void msft_do_open(struct hci_dev *hdev)
/* Monitors get removed on power off, so we need to explicitly
* tell the controller to re-monitor.
*/
- reregister_monitor_on_restart(hdev, 0);
+ reregister_monitor(hdev, 0);
}
}
@@ -382,8 +448,7 @@ static void msft_le_monitor_advertisement_cb(struct hci_dev *hdev,
/* If in restart/reregister sequence, keep registering. */
if (msft->reregistering)
- reregister_monitor_on_restart(hdev,
- msft->pending_add_handle + 1);
+ reregister_monitor(hdev, msft->pending_add_handle + 1);
hci_dev_unlock(hdev);
@@ -420,13 +485,25 @@ static void msft_le_cancel_monitor_advertisement_cb(struct hci_dev *hdev,
if (handle_data) {
monitor = idr_find(&hdev->adv_monitors_idr,
handle_data->mgmt_handle);
- if (monitor)
+
+ if (monitor && monitor->state == ADV_MONITOR_STATE_OFFLOADED)
+ monitor->state = ADV_MONITOR_STATE_REGISTERED;
+
+ /* Do not free the monitor if it is being removed due to
+ * suspend. It will be re-monitored on resume.
+ */
+ if (monitor && !msft->suspending)
hci_free_adv_monitor(hdev, monitor);
list_del(&handle_data->list);
kfree(handle_data);
}
+ /* If in suspend/remove sequence, keep removing. */
+ if (msft->suspending)
+ remove_monitor_on_suspend(hdev,
+ msft->pending_remove_handle + 1);
+
/* If remove all monitors is required, we need to continue the process
* here because the earlier it was paused when waiting for the
* response from controller.
@@ -445,7 +522,8 @@ static void msft_le_cancel_monitor_advertisement_cb(struct hci_dev *hdev,
hci_dev_unlock(hdev);
done:
- hci_remove_adv_monitor_complete(hdev, status);
+ if (!msft->suspending)
+ hci_remove_adv_monitor_complete(hdev, status);
}
static void msft_le_set_advertisement_filter_enable_cb(struct hci_dev *hdev,
@@ -578,15 +656,15 @@ int msft_add_monitor_pattern(struct hci_dev *hdev, struct adv_monitor *monitor)
if (!msft)
return -EOPNOTSUPP;
- if (msft->reregistering)
+ if (msft->reregistering || msft->suspending)
return -EBUSY;
return __msft_add_monitor_pattern(hdev, monitor);
}
/* This function requires the caller holds hdev->lock */
-int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor,
- u16 handle)
+static int __msft_remove_monitor(struct hci_dev *hdev,
+ struct adv_monitor *monitor, u16 handle)
{
struct msft_cp_le_cancel_monitor_advertisement cp;
struct msft_monitor_advertisement_handle_data *handle_data;
@@ -594,12 +672,6 @@ int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor,
struct msft_data *msft = hdev->msft_data;
int err = 0;
- if (!msft)
- return -EOPNOTSUPP;
-
- if (msft->reregistering)
- return -EBUSY;
-
handle_data = msft_find_handle_data(hdev, monitor->handle, true);
/* If no matched handle, just remove without telling controller */
@@ -619,6 +691,21 @@ int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor,
return err;
}
+/* This function requires the caller holds hdev->lock */
+int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor,
+ u16 handle)
+{
+ struct msft_data *msft = hdev->msft_data;
+
+ if (!msft)
+ return -EOPNOTSUPP;
+
+ if (msft->reregistering || msft->suspending)
+ return -EBUSY;
+
+ return __msft_remove_monitor(hdev, monitor, handle);
+}
+
void msft_req_add_set_filter_enable(struct hci_request *req, bool enable)
{
struct hci_dev *hdev = req->hdev;
diff --git a/net/bluetooth/msft.h b/net/bluetooth/msft.h
index 8018948c5975..6ec843b94d16 100644
--- a/net/bluetooth/msft.h
+++ b/net/bluetooth/msft.h
@@ -24,6 +24,8 @@ int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor,
u16 handle);
void msft_req_add_set_filter_enable(struct hci_request *req, bool enable);
int msft_set_filter_enable(struct hci_dev *hdev, bool enable);
+void msft_remove_all_monitors_on_suspend(struct hci_dev *hdev);
+void msft_reregister_monitors_on_resume(struct hci_dev *hdev);
bool msft_curve_validity(struct hci_dev *hdev);
#else
@@ -59,6 +61,9 @@ static inline int msft_set_filter_enable(struct hci_dev *hdev, bool enable)
return -EOPNOTSUPP;
}
+void msft_remove_all_monitors_on_suspend(struct hci_dev *hdev) {}
+void msft_reregister_monitors_on_resume(struct hci_dev *hdev) {}
+
static inline bool msft_curve_validity(struct hci_dev *hdev)
{
return false;
--
2.33.0.464.g1972c5931b-goog