[PATCH v2 0/3] Bluetooth: Emit events for suspend/resume

[PATCH v2 0/3] Bluetooth: Emit events for suspend/resume

[Abhishek Pandit-Subedi]

Hi Marcel,

This series adds the suspend/resume events suggested in
https://patchwork.kernel.org/patch/11771001/.

I have tested it with some userspace changes that monitors the
controller resumed event to trigger audio device reconnection and
verified that the events are correctly emitted.

Patch for btmon changes: https://patchwork.kernel.org/patch/11743863/

Please take a look.
Abhishek

Changes in v2:
- Added suspend/resume events to list of mgmt events

Abhishek Pandit-Subedi (3):
  Bluetooth: Add mgmt suspend and resume events
  Bluetooth: Add suspend reason for device disconnect
  Bluetooth: Emit controller suspend and resume events

 include/net/bluetooth/hci_core.h |  6 +++
 include/net/bluetooth/mgmt.h     | 16 +++++++
 net/bluetooth/hci_core.c         | 26 +++++++++++-
 net/bluetooth/hci_event.c        | 73 ++++++++++++++++++++++++++++++++
 net/bluetooth/mgmt.c             | 30 +++++++++++++
 5 files changed, 150 insertions(+), 1 deletion(-)

-- 
2.28.0.618.gf4bc123cb7-goog

[PATCH v2 1/3] Bluetooth: Add mgmt suspend and resume events

[Abhishek Pandit-Subedi]

Add the controller suspend and resume events, which will signal when
Bluetooth has completed preparing for suspend and when it's ready for
resume.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Reviewed-by: Sonny Sasaka <sonnysasaka@chromium.org>
---

Changes in v2:
- Added suspend/resume events to list of mgmt events

 include/net/bluetooth/hci_core.h |  3 +++
 include/net/bluetooth/mgmt.h     | 11 +++++++++++
 net/bluetooth/mgmt.c             | 26 ++++++++++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 8caac20556b499..02a6ee056b2374 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1750,6 +1750,9 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 void mgmt_remote_name(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 		      u8 addr_type, s8 rssi, u8 *name, u8 name_len);
 void mgmt_discovering(struct hci_dev *hdev, u8 discovering);
+void mgmt_suspending(struct hci_dev *hdev, u8 state);
+void mgmt_resuming(struct hci_dev *hdev, u8 reason, bdaddr_t *bdaddr,
+		   u8 addr_type);
 bool mgmt_powering_down(struct hci_dev *hdev);
 void mgmt_new_ltk(struct hci_dev *hdev, struct smp_ltk *key, bool persistent);
 void mgmt_new_irk(struct hci_dev *hdev, struct smp_irk *irk, bool persistent);
diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index 9ad505b9e694e4..e19e33c7b65c34 100644
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -1030,3 +1030,14 @@ struct mgmt_ev_adv_monitor_added {
 struct mgmt_ev_adv_monitor_removed {
 	__le16 monitor_handle;
 }  __packed;
+
+#define MGMT_EV_CONTROLLER_SUSPEND		0x002d
+struct mgmt_ev_controller_suspend {
+	__u8	suspend_state;
+} __packed;
+
+#define MGMT_EV_CONTROLLER_RESUME		0x002e
+struct mgmt_ev_controller_resume {
+	__u8	wake_reason;
+	struct mgmt_addr_info addr;
+} __packed;
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index e1d12494d16e14..db48ee3c213cbd 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -163,6 +163,8 @@ static const u16 mgmt_events[] = {
 	MGMT_EV_PHY_CONFIGURATION_CHANGED,
 	MGMT_EV_EXP_FEATURE_CHANGED,
 	MGMT_EV_DEVICE_FLAGS_CHANGED,
+	MGMT_EV_CONTROLLER_SUSPEND,
+	MGMT_EV_CONTROLLER_RESUME,
 };
 
 static const u16 mgmt_untrusted_commands[] = {
@@ -8874,6 +8876,30 @@ void mgmt_discovering(struct hci_dev *hdev, u8 discovering)
 	mgmt_event(MGMT_EV_DISCOVERING, hdev, &ev, sizeof(ev), NULL);
 }
 
+void mgmt_suspending(struct hci_dev *hdev, u8 state)
+{
+	struct mgmt_ev_controller_suspend ev;
+
+	ev.suspend_state = state;
+	mgmt_event(MGMT_EV_CONTROLLER_SUSPEND, hdev, &ev, sizeof(ev), NULL);
+}
+
+void mgmt_resuming(struct hci_dev *hdev, u8 reason, bdaddr_t *bdaddr,
+		   u8 addr_type)
+{
+	struct mgmt_ev_controller_resume ev;
+
+	ev.wake_reason = reason;
+	if (bdaddr) {
+		bacpy(&ev.addr.bdaddr, bdaddr);
+		ev.addr.type = addr_type;
+	} else {
+		memset(&ev.addr, 0, sizeof(ev.addr));
+	}
+
+	mgmt_event(MGMT_EV_CONTROLLER_RESUME, hdev, &ev, sizeof(ev), NULL);
+}
+
 static struct hci_mgmt_chan chan = {
 	.channel	= HCI_CHANNEL_CONTROL,
 	.handler_count	= ARRAY_SIZE(mgmt_handlers),
-- 
2.28.0.618.gf4bc123cb7-goog

[PATCH v2 2/3] Bluetooth: Add suspend reason for device disconnect

[Abhishek Pandit-Subedi]

Update device disconnect event with reason 0x5 to indicate that device
disconnected because the controller is suspending.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Reviewed-by: Sonny Sasaka <sonnysasaka@chromium.org>
---

Changes in v2: None

 include/net/bluetooth/mgmt.h | 1 +
 net/bluetooth/mgmt.c         | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index e19e33c7b65c34..a4b8935e0db97a 100644
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -842,6 +842,7 @@ struct mgmt_ev_device_connected {
 #define MGMT_DEV_DISCONN_LOCAL_HOST	0x02
 #define MGMT_DEV_DISCONN_REMOTE		0x03
 #define MGMT_DEV_DISCONN_AUTH_FAILURE	0x04
+#define MGMT_DEV_DISCONN_LOCAL_HOST_SUSPEND	0x05
 
 #define MGMT_EV_DEVICE_DISCONNECTED	0x000C
 struct mgmt_ev_device_disconnected {
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index db48ee3c213cbd..0b711ad80f6bd1 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -8270,6 +8270,10 @@ void mgmt_device_disconnected(struct hci_dev *hdev, bdaddr_t *bdaddr,
 	ev.addr.type = link_to_bdaddr(link_type, addr_type);
 	ev.reason = reason;
 
+	/* Report disconnects due to suspend */
+	if (hdev->suspended)
+		ev.reason = MGMT_DEV_DISCONN_LOCAL_HOST_SUSPEND;
+
 	mgmt_event(MGMT_EV_DEVICE_DISCONNECTED, hdev, &ev, sizeof(ev), sk);
 
 	if (sk)
-- 
2.28.0.618.gf4bc123cb7-goog

[PATCH v2 3/3] Bluetooth: Emit controller suspend and resume events

[Abhishek Pandit-Subedi]

Emit controller suspend and resume events when we are ready for suspend
and we've resumed from suspend.

The controller suspend event will report whatever suspend state was
successfully entered. The controller resume event will check the first
HCI event that was received after we finished preparing for suspend and,
if it was a connection event, store the address of the peer that caused
the event. If it was not a connection event, we mark the wake reason as
an unexpected event.

Here is a sample btmon trace with these events:

@ MGMT Event: Controller Suspended (0x002d) plen 1
        Suspend state: Page scanning and/or passive scanning (2)

@ MGMT Event: Controller Resumed (0x002e) plen 8
        Wake reason: Remote wake due to peer device connection (2)
        LE Address: CD:F3:CD:13:C5:9A (OUI CD-F3-CD)

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
---

Changes in v2: None

 include/net/bluetooth/hci_core.h |  3 ++
 include/net/bluetooth/mgmt.h     |  4 ++
 net/bluetooth/hci_core.c         | 26 +++++++++++-
 net/bluetooth/hci_event.c        | 73 ++++++++++++++++++++++++++++++++
 4 files changed, 105 insertions(+), 1 deletion(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 02a6ee056b2374..9873e1c8cd163b 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -484,6 +484,9 @@ struct hci_dev {
 	enum suspended_state	suspend_state;
 	bool			scanning_paused;
 	bool			suspended;
+	u8			wake_reason;
+	bdaddr_t		wake_addr;
+	u8			wake_addr_type;
 
 	wait_queue_head_t	suspend_wait_q;
 	DECLARE_BITMAP(suspend_tasks, __SUSPEND_NUM_TASKS);
diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index a4b8935e0db97a..6b55155e05e977 100644
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -1042,3 +1042,7 @@ struct mgmt_ev_controller_resume {
 	__u8	wake_reason;
 	struct mgmt_addr_info addr;
 } __packed;
+
+#define MGMT_WAKE_REASON_NON_BT_WAKE		0x0
+#define MGMT_WAKE_REASON_UNEXPECTED		0x1
+#define MGMT_WAKE_REASON_REMOTE_WAKE		0x2
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index ef32b12f150cd1..8a2645a8330137 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3497,12 +3497,24 @@ static int hci_change_suspend_state(struct hci_dev *hdev,
 	return hci_suspend_wait_event(hdev);
 }
 
+static void hci_clear_wake_reason(struct hci_dev *hdev)
+{
+	hci_dev_lock(hdev);
+
+	hdev->wake_reason = 0;
+	bacpy(&hdev->wake_addr, BDADDR_ANY);
+	hdev->wake_addr_type = 0;
+
+	hci_dev_unlock(hdev);
+}
+
 static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action,
 				void *data)
 {
 	struct hci_dev *hdev =
 		container_of(nb, struct hci_dev, suspend_notifier);
 	int ret = 0;
+	u8 state = BT_RUNNING;
 
 	/* If powering down, wait for completion. */
 	if (mgmt_powering_down(hdev)) {
@@ -3523,15 +3535,27 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action,
 		 *  - Second, program event filter/whitelist and enable scan
 		 */
 		ret = hci_change_suspend_state(hdev, BT_SUSPEND_DISCONNECT);
+		if (!ret)
+			state = BT_SUSPEND_DISCONNECT;
 
 		/* Only configure whitelist if disconnect succeeded and wake
 		 * isn't being prevented.
 		 */
-		if (!ret && !(hdev->prevent_wake && hdev->prevent_wake(hdev)))
+		if (!ret && !(hdev->prevent_wake && hdev->prevent_wake(hdev))) {
 			ret = hci_change_suspend_state(hdev,
 						BT_SUSPEND_CONFIGURE_WAKE);
+			if (!ret)
+				state = BT_SUSPEND_CONFIGURE_WAKE;
+		}
+
+		hci_clear_wake_reason(hdev);
+		mgmt_suspending(hdev, state);
+
 	} else if (action == PM_POST_SUSPEND) {
 		ret = hci_change_suspend_state(hdev, BT_RUNNING);
+
+		mgmt_resuming(hdev, hdev->wake_reason, &hdev->wake_addr,
+			      hdev->wake_addr_type);
 	}
 
 done:
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 33d8458fdd4adc..a68be50097ac35 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -6000,6 +6000,76 @@ static bool hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
 	return true;
 }
 
+static void hci_store_wake_reason(struct hci_dev *hdev, u8 event,
+				  struct sk_buff *skb)
+{
+	struct hci_ev_le_advertising_info *adv;
+	struct hci_ev_le_direct_adv_info *direct_adv;
+	struct hci_ev_le_ext_adv_report *ext_adv;
+	const struct hci_ev_conn_complete *conn_complete = (void *)skb->data;
+	const struct hci_ev_conn_request *conn_request = (void *)skb->data;
+
+	hci_dev_lock(hdev);
+
+	/* If we are currently suspended and this is the first BT event seen,
+	 * save the wake reason associated with the event.
+	 */
+	if (!hdev->suspended || hdev->wake_reason)
+		goto unlock;
+
+	/* Default to remote wake. Values for wake_reason are documented in the
+	 * Bluez mgmt api docs.
+	 */
+	hdev->wake_reason = MGMT_WAKE_REASON_REMOTE_WAKE;
+
+	/* Once configured for remote wakeup, we should only wake up for
+	 * reconnections. It's useful to see which device is waking us up so
+	 * keep track of the bdaddr of the connection event that woke us up.
+	 */
+	if (event == HCI_EV_CONN_REQUEST) {
+		bacpy(&hdev->wake_addr, &conn_complete->bdaddr);
+		hdev->wake_addr_type = BDADDR_BREDR;
+	} else if (event == HCI_EV_CONN_COMPLETE) {
+		bacpy(&hdev->wake_addr, &conn_request->bdaddr);
+		hdev->wake_addr_type = BDADDR_BREDR;
+	} else if (event == HCI_EV_LE_META) {
+		struct hci_ev_le_meta *le_ev = (void *)skb->data;
+		u8 subevent = le_ev->subevent;
+		u8 *ptr = &skb->data[sizeof(*le_ev)];
+		u8 num_reports = *ptr;
+
+		if ((subevent == HCI_EV_LE_ADVERTISING_REPORT ||
+		     subevent == HCI_EV_LE_DIRECT_ADV_REPORT ||
+		     subevent == HCI_EV_LE_EXT_ADV_REPORT) &&
+		    num_reports) {
+			adv = (void *)(ptr + 1);
+			direct_adv = (void *)(ptr + 1);
+			ext_adv = (void *)(ptr + 1);
+
+			switch (subevent) {
+			case HCI_EV_LE_ADVERTISING_REPORT:
+				bacpy(&hdev->wake_addr, &adv->bdaddr);
+				hdev->wake_addr_type = adv->bdaddr_type;
+				break;
+
+			case HCI_EV_LE_DIRECT_ADV_REPORT:
+				bacpy(&hdev->wake_addr, &direct_adv->bdaddr);
+				hdev->wake_addr_type = direct_adv->bdaddr_type;
+				break;
+			case HCI_EV_LE_EXT_ADV_REPORT:
+				bacpy(&hdev->wake_addr, &ext_adv->bdaddr);
+				hdev->wake_addr_type = ext_adv->bdaddr_type;
+				break;
+			}
+		}
+	} else {
+		hdev->wake_reason = MGMT_WAKE_REASON_UNEXPECTED;
+	}
+
+unlock:
+	hci_dev_unlock(hdev);
+}
+
 void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_event_hdr *hdr = (void *) skb->data;
@@ -6033,6 +6103,9 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 
 	skb_pull(skb, HCI_EVENT_HDR_SIZE);
 
+	/* Store wake reason if we're suspended */
+	hci_store_wake_reason(hdev, event, skb);
+
 	switch (event) {
 	case HCI_EV_INQUIRY_COMPLETE:
 		hci_inquiry_complete_evt(hdev, skb);
-- 
2.28.0.618.gf4bc123cb7-goog

Re: [PATCH v2 0/3] Bluetooth: Emit events for suspend/resume

[Marcel Holtmann]

Hi Abhishek,

> This series adds the suspend/resume events suggested in
> https://patchwork.kernel.org/patch/11771001/.
> 
> I have tested it with some userspace changes that monitors the
> controller resumed event to trigger audio device reconnection and
> verified that the events are correctly emitted.
> 
> Patch for btmon changes: https://patchwork.kernel.org/patch/11743863/
> 
> Please take a look.
> Abhishek
> 
> Changes in v2:
> - Added suspend/resume events to list of mgmt events
> 
> Abhishek Pandit-Subedi (3):
>  Bluetooth: Add mgmt suspend and resume events
>  Bluetooth: Add suspend reason for device disconnect
>  Bluetooth: Emit controller suspend and resume events
> 
> include/net/bluetooth/hci_core.h |  6 +++
> include/net/bluetooth/mgmt.h     | 16 +++++++
> net/bluetooth/hci_core.c         | 26 +++++++++++-
> net/bluetooth/hci_event.c        | 73 ++++++++++++++++++++++++++++++++
> net/bluetooth/mgmt.c             | 30 +++++++++++++
> 5 files changed, 150 insertions(+), 1 deletion(-)

All 3 patches have been applied to bluetooth-next tree.

Regards

Marcel