[RFC PATCH v5 0/5] Bluetooth: Handle system suspend gracefully

[RFC PATCH v5 0/5] Bluetooth: Handle system suspend gracefully

[Abhishek Pandit-Subedi]

Hi linux-bluetooth,

This patch series prepares the Bluetooth controller for system suspend
by disconnecting all devices and preparing the event filter and LE
whitelist with devices that can wake the system from suspend.

The main motivation for doing this is so we can enable Bluetooth as
a wake up source during suspend without it being noisy. Bluetooth should
wake the system when a HID device receives user input but otherwise not
send any events to the host.

This patch series was tested on several Chromebooks with both btusb and
hci_serdev on kernel 4.19. The set of tests was basically the following:
* Reconnects after suspend succeed
* HID devices can wake the system from suspend (needs some related bluez
  changes to call the Set Wake Capable management command)
* System properly pauses and unpauses discovery + advertising around
  suspend
* System does not wake from any events from non wakeable devices

Series 2 has refactored the change into multiple smaller commits as
requested. I tried to simplify some of the whitelist filtering edge
cases but unfortunately it remains quite complex.

Series 3 has refactored it further and should have resolved the
whitelisting complexity in series 2.

Series 4 adds a fix to check for powered down and powering down adapters.

Series 5 moves set_wake_capable to the last patch in the series and
changes BT_DBG to bt_dev_dbg.

Please review and provide any feedback.

Thanks
Abhishek


Changes in v5:
* Convert BT_DBG to bt_dev_dbg
* Added wakeable list and changed BT_DBG to bt_dev_dbg
* Add wakeable to hci_conn_params and change BT_DBG to bt_dev_dbg
* Changed BT_DBG to bt_dev_dbg
* Wakeable entries moved to other commits
* Patch moved to end of series

Changes in v4:
* Added check for mgmt_powering_down and hdev_is_powered in notifier

Changes in v3:
* Refactored to only handle BR/EDR devices
* Split LE changes into its own commit
* Added wakeable property to le_conn_param
* Use wakeable list for BR/EDR and wakeable property for LE

Changes in v2:
* Moved pm notifier registration into its own patch and moved params out
  of separate suspend_state
* Refactored filters and whitelist settings to its own patch
* Refactored update_white_list to have clearer edge cases
* Add connected devices to whitelist (previously missing corner case)
* Refactored pause discovery + advertising into its own patch

Abhishek Pandit-Subedi (5):
  Bluetooth: Handle PM_SUSPEND_PREPARE and PM_POST_SUSPEND
  Bluetooth: Handle BR/EDR devices during suspend
  Bluetooth: Handle LE devices during suspend
  Bluetooth: Pause discovery and advertising during suspend
  Bluetooth: Add mgmt op set_wake_capable

 include/net/bluetooth/hci.h      |  17 +-
 include/net/bluetooth/hci_core.h |  43 ++++
 include/net/bluetooth/mgmt.h     |   7 +
 net/bluetooth/hci_core.c         | 102 ++++++++++
 net/bluetooth/hci_event.c        |  24 +++
 net/bluetooth/hci_request.c      | 331 ++++++++++++++++++++++++++-----
 net/bluetooth/hci_request.h      |   2 +
 net/bluetooth/mgmt.c             |  92 +++++++++
 8 files changed, 558 insertions(+), 60 deletions(-)

-- 
2.25.1.481.gfbce0eb801-goog

[RFC PATCH v5 1/5] Bluetooth: Handle PM_SUSPEND_PREPARE and PM_POST_SUSPEND

[Abhishek Pandit-Subedi]

Register for PM_SUSPEND_PREPARE and PM_POST_SUSPEND to make sure the
Bluetooth controller is prepared correctly for suspend/resume. Implement
the registration, scheduling and task handling portions only in this
patch.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v5:
* Convert BT_DBG to bt_dev_dbg

Changes in v4:
* Added check for mgmt_powering_down and hdev_is_powered in notifier

Changes in v3: None
Changes in v2:
* Moved pm notifier registration into its own patch and moved params out
  of separate suspend_state

 include/net/bluetooth/hci_core.h | 23 +++++++++
 net/bluetooth/hci_core.c         | 86 ++++++++++++++++++++++++++++++++
 net/bluetooth/hci_request.c      | 19 +++++++
 net/bluetooth/hci_request.h      |  2 +
 4 files changed, 130 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index c498ac113930..d6f694b436bf 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -88,6 +88,20 @@ struct discovery_state {
 	unsigned long		scan_duration;
 };
 
+#define SUSPEND_NOTIFIER_TIMEOUT	msecs_to_jiffies(2000) /* 2 seconds */
+
+enum suspend_tasks {
+	SUSPEND_POWERING_DOWN,
+
+	SUSPEND_PREPARE_NOTIFIER,
+	__SUSPEND_NUM_TASKS
+};
+
+enum suspended_state {
+	BT_RUNNING = 0,
+	BT_SUSPENDED,
+};
+
 struct hci_conn_hash {
 	struct list_head list;
 	unsigned int     acl_num;
@@ -390,6 +404,15 @@ struct hci_dev {
 	void			*smp_bredr_data;
 
 	struct discovery_state	discovery;
+
+	struct notifier_block	suspend_notifier;
+	struct work_struct	suspend_prepare;
+	enum suspended_state	suspend_state_next;
+	enum suspended_state	suspend_state;
+
+	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;
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 9ce98762559b..2286b556c69e 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -31,6 +31,8 @@
 #include <linux/debugfs.h>
 #include <linux/crypto.h>
 #include <linux/property.h>
+#include <linux/suspend.h>
+#include <linux/wait.h>
 #include <asm/unaligned.h>
 
 #include <net/bluetooth/bluetooth.h>
@@ -1787,6 +1789,9 @@ int hci_dev_do_close(struct hci_dev *hdev)
 	clear_bit(HCI_RUNNING, &hdev->flags);
 	hci_sock_dev_event(hdev, HCI_DEV_CLOSE);
 
+	if (test_and_clear_bit(SUSPEND_POWERING_DOWN, hdev->suspend_tasks))
+		wake_up(&hdev->suspend_wait_q);
+
 	/* After this point our queues are empty
 	 * and no tasks are scheduled. */
 	hdev->close(hdev);
@@ -3264,6 +3269,78 @@ void hci_copy_identity_address(struct hci_dev *hdev, bdaddr_t *bdaddr,
 	}
 }
 
+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_dbg(hdev, "Timed out waiting for suspend");
+		for (i = 0; i < __SUSPEND_NUM_TASKS; ++i) {
+			if (test_bit(i, hdev->suspend_tasks))
+				bt_dev_dbg(hdev, "Bit %d is set", 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_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;
+
+	/* 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 notifier should only act on events when powered. */
+	if (!hdev_is_powered(hdev))
+		goto done;
+
+	if (action == PM_SUSPEND_PREPARE) {
+		hdev->suspend_state_next = BT_SUSPENDED;
+		set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
+		queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
+
+		ret = hci_suspend_wait_event(hdev);
+	} else if (action == PM_POST_SUSPEND) {
+		hdev->suspend_state_next = BT_RUNNING;
+		set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
+		queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
+
+		ret = hci_suspend_wait_event(hdev);
+	}
+
+done:
+	return ret ? notifier_from_errno(-EBUSY) : NOTIFY_STOP;
+}
 /* Alloc HCI device */
 struct hci_dev *hci_alloc_dev(void)
 {
@@ -3341,6 +3418,7 @@ struct hci_dev *hci_alloc_dev(void)
 	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);
 
 	INIT_DELAYED_WORK(&hdev->power_off, hci_power_off);
 
@@ -3349,6 +3427,7 @@ struct hci_dev *hci_alloc_dev(void)
 	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);
 
@@ -3460,6 +3539,11 @@ int hci_register_dev(struct hci_dev *hdev)
 	hci_sock_dev_event(hdev, HCI_DEV_REG);
 	hci_dev_hold(hdev);
 
+	hdev->suspend_notifier.notifier_call = hci_suspend_notifier;
+	error = register_pm_notifier(&hdev->suspend_notifier);
+	if (error)
+		goto err_wqueue;
+
 	queue_work(hdev->req_workqueue, &hdev->power_on);
 
 	return id;
@@ -3493,6 +3577,8 @@ void hci_unregister_dev(struct hci_dev *hdev)
 
 	hci_dev_do_close(hdev);
 
+	unregister_pm_notifier(&hdev->suspend_notifier);
+
 	if (!test_bit(HCI_INIT, &hdev->flags) &&
 	    !hci_dev_test_flag(hdev, HCI_SETUP) &&
 	    !hci_dev_test_flag(hdev, HCI_CONFIG)) {
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 2a1b64dbf76e..1c5a76df1ded 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -918,6 +918,25 @@ static u8 get_adv_instance_scan_rsp_len(struct hci_dev *hdev, u8 instance)
 	return adv_instance->scan_rsp_len;
 }
 
+/* Call with hci_dev_lock */
+void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
+{
+	int old_state;
+	struct hci_conn *conn;
+	struct hci_request req;
+
+	if (next == hdev->suspend_state) {
+		bt_dev_dbg(hdev, "Same state before and after: %d", next);
+		goto done;
+	}
+
+	hdev->suspend_state = next;
+
+done:
+	clear_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
+	wake_up(&hdev->suspend_wait_q);
+}
+
 static u8 get_cur_adv_instance_scan_rsp_len(struct hci_dev *hdev)
 {
 	u8 instance = hdev->cur_adv_instance;
diff --git a/net/bluetooth/hci_request.h b/net/bluetooth/hci_request.h
index a7019fbeadd3..0e81614d235e 100644
--- a/net/bluetooth/hci_request.h
+++ b/net/bluetooth/hci_request.h
@@ -68,6 +68,8 @@ void __hci_req_update_eir(struct hci_request *req);
 void hci_req_add_le_scan_disable(struct hci_request *req);
 void hci_req_add_le_passive_scan(struct hci_request *req);
 
+void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next);
+
 void hci_req_reenable_advertising(struct hci_dev *hdev);
 void __hci_req_enable_advertising(struct hci_request *req);
 void __hci_req_disable_advertising(struct hci_request *req);
-- 
2.25.1.481.gfbce0eb801-goog

Re: [RFC PATCH v5 1/5] Bluetooth: Handle PM_SUSPEND_PREPARE and PM_POST_SUSPEND

[Marcel Holtmann]

Hi Abhishek,

> Register for PM_SUSPEND_PREPARE and PM_POST_SUSPEND to make sure the
> Bluetooth controller is prepared correctly for suspend/resume. Implement
> the registration, scheduling and task handling portions only in this
> patch.

is the kernel test robot bug report that just has been posted still valid?

Regards

Marcel

Re: [RFC PATCH v5 1/5] Bluetooth: Handle PM_SUSPEND_PREPARE and PM_POST_SUSPEND

[Abhishek Pandit-Subedi]

No -- the kernel test robot is complaining about Patch v3 which has a
known problem (not taking into powered state into account). That was
fixed in v4.

Thanks,
Abhishek

On Mon, Mar 9, 2020 at 2:39 PM Marcel Holtmann <marcel@holtmann.org> wrote:
>
> Hi Abhishek,
>
> > Register for PM_SUSPEND_PREPARE and PM_POST_SUSPEND to make sure the
> > Bluetooth controller is prepared correctly for suspend/resume. Implement
> > the registration, scheduling and task handling portions only in this
> > patch.
>
> is the kernel test robot bug report that just has been posted still valid?
>
> Regards
>
> Marcel
>

[RFC PATCH v5 2/5] Bluetooth: Handle BR/EDR devices during suspend

[Abhishek Pandit-Subedi]

To handle BR/EDR devices, we first disable page scan and disconnect all
connected devices. Once that is complete, we add event filters (for
devices that can wake the system) and re-enable page scan.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v5:
* Added wakeable list and changed BT_DBG to bt_dev_dbg

Changes in v4: None
Changes in v3:
* Refactored to only handle BR/EDR devices

Changes in v2:
* Refactored filters and whitelist settings to its own patch
* Refactored update_white_list to have clearer edge cases
* Add connected devices to whitelist (previously missing corner case)

 include/net/bluetooth/hci.h      |  17 +++--
 include/net/bluetooth/hci_core.h |  10 ++-
 net/bluetooth/hci_core.c         |  22 ++++++-
 net/bluetooth/hci_event.c        |  24 +++++++
 net/bluetooth/hci_request.c      | 103 +++++++++++++++++++++++++++++++
 5 files changed, 166 insertions(+), 10 deletions(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 4e86f1bb7a87..5f60e135aeb6 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -942,10 +942,14 @@ struct hci_cp_sniff_subrate {
 #define HCI_OP_RESET			0x0c03
 
 #define HCI_OP_SET_EVENT_FLT		0x0c05
-struct hci_cp_set_event_flt {
-	__u8     flt_type;
-	__u8     cond_type;
-	__u8     condition[];
+#define HCI_SET_EVENT_FLT_SIZE		9
+struct hci_cp_set_event_filter {
+	__u8		flt_type;
+	__u8		cond_type;
+	struct {
+		bdaddr_t bdaddr;
+		__u8 auto_accept;
+	} __packed	addr_conn_flt;
 } __packed;
 
 /* Filter types */
@@ -959,8 +963,9 @@ struct hci_cp_set_event_flt {
 #define HCI_CONN_SETUP_ALLOW_BDADDR	0x02
 
 /* CONN_SETUP Conditions */
-#define HCI_CONN_SETUP_AUTO_OFF	0x01
-#define HCI_CONN_SETUP_AUTO_ON	0x02
+#define HCI_CONN_SETUP_AUTO_OFF		0x01
+#define HCI_CONN_SETUP_AUTO_ON		0x02
+#define HCI_CONN_SETUP_AUTO_ON_WITH_RS	0x03
 
 #define HCI_OP_READ_STORED_LINK_KEY	0x0c0d
 struct hci_cp_read_stored_link_key {
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index d6f694b436bf..1a4d732bdce6 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -91,6 +91,10 @@ struct discovery_state {
 #define SUSPEND_NOTIFIER_TIMEOUT	msecs_to_jiffies(2000) /* 2 seconds */
 
 enum suspend_tasks {
+	SUSPEND_SCAN_DISABLE,
+	SUSPEND_SCAN_ENABLE,
+	SUSPEND_DISCONNECTING,
+
 	SUSPEND_POWERING_DOWN,
 
 	SUSPEND_PREPARE_NOTIFIER,
@@ -99,7 +103,8 @@ enum suspend_tasks {
 
 enum suspended_state {
 	BT_RUNNING = 0,
-	BT_SUSPENDED,
+	BT_SUSPEND_DISCONNECT,
+	BT_SUSPEND_COMPLETE,
 };
 
 struct hci_conn_hash {
@@ -409,6 +414,8 @@ struct hci_dev {
 	struct work_struct	suspend_prepare;
 	enum suspended_state	suspend_state_next;
 	enum suspended_state	suspend_state;
+	bool			scanning_paused;
+	bool			suspended;
 
 	wait_queue_head_t	suspend_wait_q;
 	DECLARE_BITMAP(suspend_tasks, __SUSPEND_NUM_TASKS);
@@ -418,6 +425,7 @@ struct hci_dev {
 	struct list_head	mgmt_pending;
 	struct list_head	blacklist;
 	struct list_head	whitelist;
+	struct list_head	wakeable;
 	struct list_head	uuids;
 	struct list_head	link_keys;
 	struct list_head	long_term_keys;
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2286b556c69e..24f2e4bf5d66 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3325,16 +3325,31 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action,
 		goto done;
 
 	if (action == PM_SUSPEND_PREPARE) {
-		hdev->suspend_state_next = BT_SUSPENDED;
+		/* Suspend consists of two actions:
+		 *  - First, disconnect everything and make the controller not
+		 *    connectable (disabling scanning)
+		 *  - Second, program event filter/whitelist and enable scan
+		 */
+		hdev->suspend_state_next = BT_SUSPEND_DISCONNECT;
 		set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
 		queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
-
 		ret = hci_suspend_wait_event(hdev);
+
+		/* If the disconnect portion failed, don't attempt to complete
+		 * by configuring the whitelist. The suspend notifier will
+		 * follow a cancelled suspend with a PM_POST_SUSPEND
+		 * notification.
+		 */
+		if (!ret) {
+			hdev->suspend_state_next = BT_SUSPEND_COMPLETE;
+			set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
+			queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
+			ret = hci_suspend_wait_event(hdev);
+		}
 	} else if (action == PM_POST_SUSPEND) {
 		hdev->suspend_state_next = BT_RUNNING;
 		set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
 		queue_work(hdev->req_workqueue, &hdev->suspend_prepare);
-
 		ret = hci_suspend_wait_event(hdev);
 	}
 
@@ -3399,6 +3414,7 @@ struct hci_dev *hci_alloc_dev(void)
 	INIT_LIST_HEAD(&hdev->mgmt_pending);
 	INIT_LIST_HEAD(&hdev->blacklist);
 	INIT_LIST_HEAD(&hdev->whitelist);
+	INIT_LIST_HEAD(&hdev->wakeable);
 	INIT_LIST_HEAD(&hdev->uuids);
 	INIT_LIST_HEAD(&hdev->link_keys);
 	INIT_LIST_HEAD(&hdev->long_term_keys);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index b9186026508e..0908eaa7cacf 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2505,6 +2505,7 @@ static void hci_inquiry_result_evt(struct hci_dev *hdev, struct sk_buff *skb)
 static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_conn_complete *ev = (void *) skb->data;
+	struct inquiry_entry *ie;
 	struct hci_conn *conn;
 
 	BT_DBG("%s", hdev->name);
@@ -2513,6 +2514,21 @@ static void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 
 	conn = hci_conn_hash_lookup_ba(hdev, ev->link_type, &ev->bdaddr);
 	if (!conn) {
+		/* Connection may not exist if auto-connected. Check the inquiry
+		 * cache to see if we've already discovered this bdaddr before.
+		 * If found and link is an ACL type, create a connection class
+		 * automatically.
+		 */
+		ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
+		if (ie && ev->link_type == ACL_LINK) {
+			conn = hci_conn_add(hdev, ev->link_type, &ev->bdaddr,
+					    HCI_ROLE_SLAVE);
+			if (!conn) {
+				bt_dev_err(hdev, "no memory for new conn");
+				goto unlock;
+			}
+		}
+
 		if (ev->link_type != SCO_LINK)
 			goto unlock;
 
@@ -2774,6 +2790,14 @@ static void hci_disconn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 	hci_disconn_cfm(conn, ev->reason);
 	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);
+	}
+
 	/* Re-enable advertising if necessary, since it might
 	 * have been disabled by the connection. From the
 	 * HCI_LE_Set_Advertise_Enable command description in
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 1c5a76df1ded..bb52aedc91b7 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -918,12 +918,63 @@ static u8 get_adv_instance_scan_rsp_len(struct hci_dev *hdev, u8 instance)
 	return adv_instance->scan_rsp_len;
 }
 
+static void hci_req_clear_event_filter(struct hci_request *req)
+{
+	struct hci_cp_set_event_filter f;
+
+	memset(&f, 0, sizeof(f));
+	f.flt_type = HCI_FLT_CLEAR_ALL;
+	hci_req_add(req, HCI_OP_SET_EVENT_FLT, 1, &f);
+
+	/* Update page scan state (since we may have modified it when setting
+	 * the event filter).
+	 */
+	__hci_req_update_scan(req);
+}
+
+static void hci_req_set_event_filter(struct hci_request *req)
+{
+	struct bdaddr_list *b;
+	struct hci_cp_set_event_filter f;
+	struct hci_dev *hdev = req->hdev;
+	u8 scan;
+
+	/* Always clear event filter when starting */
+	hci_req_clear_event_filter(req);
+
+	list_for_each_entry(b, &hdev->wakeable, list) {
+		memset(&f, 0, sizeof(f));
+		bacpy(&f.addr_conn_flt.bdaddr, &b->bdaddr);
+		f.flt_type = HCI_FLT_CONN_SETUP;
+		f.cond_type = HCI_CONN_SETUP_ALLOW_BDADDR;
+		f.addr_conn_flt.auto_accept = HCI_CONN_SETUP_AUTO_ON;
+
+		bt_dev_dbg(hdev, "Adding event filters for %pMR", &b->bdaddr);
+		hci_req_add(req, HCI_OP_SET_EVENT_FLT, sizeof(f), &f);
+	}
+
+	scan = !list_empty(&hdev->wakeable) ? SCAN_PAGE : SCAN_DISABLED;
+	hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan);
+}
+
+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,
+		   status);
+	if (test_and_clear_bit(SUSPEND_SCAN_ENABLE, hdev->suspend_tasks) ||
+	    test_and_clear_bit(SUSPEND_SCAN_DISABLE, hdev->suspend_tasks)) {
+		wake_up(&hdev->suspend_wait_q);
+	}
+}
+
 /* Call with hci_dev_lock */
 void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 {
 	int old_state;
 	struct hci_conn *conn;
 	struct hci_request req;
+	u8 page_scan;
+	int disconnect_counter;
 
 	if (next == hdev->suspend_state) {
 		bt_dev_dbg(hdev, "Same state before and after: %d", next);
@@ -931,6 +982,55 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 	}
 
 	hdev->suspend_state = next;
+	hci_req_init(&req, hdev);
+
+	if (next == BT_SUSPEND_DISCONNECT) {
+		/* Mark device as suspended */
+		hdev->suspended = true;
+
+		/* Disable page scan */
+		page_scan = SCAN_DISABLED;
+		hci_req_add(&req, HCI_OP_WRITE_SCAN_ENABLE, 1, &page_scan);
+
+		/* Mark task needing completion */
+		set_bit(SUSPEND_SCAN_DISABLE, hdev->suspend_tasks);
+
+		/* Prevent disconnects from causing scanning to be re-enabled */
+		hdev->scanning_paused = true;
+
+		/* Run commands before disconnecting */
+		hci_req_run(&req, suspend_req_complete);
+
+		disconnect_counter = 0;
+		/* Soft disconnect everything (power off) */
+		list_for_each_entry(conn, &hdev->conn_hash.list, list) {
+			hci_disconnect(conn, HCI_ERROR_REMOTE_POWER_OFF);
+			disconnect_counter++;
+		}
+
+		if (disconnect_counter > 0) {
+			bt_dev_dbg(hdev,
+				   "Had %d disconnects. Will wait on them",
+				   disconnect_counter);
+			set_bit(SUSPEND_DISCONNECTING, hdev->suspend_tasks);
+		}
+	} else if (next == BT_SUSPEND_COMPLETE) {
+		/* Unpause to take care of updating scanning params */
+		hdev->scanning_paused = false;
+		/* Enable event filter for paired devices */
+		hci_req_set_event_filter(&req);
+		/* Pause scan changes again. */
+		hdev->scanning_paused = true;
+		hci_req_run(&req, suspend_req_complete);
+	} else {
+		hdev->suspended = false;
+		hdev->scanning_paused = false;
+
+		hci_req_clear_event_filter(&req);
+		hci_req_run(&req, suspend_req_complete);
+	}
+
+	hdev->suspend_state = next;
 
 done:
 	clear_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend_tasks);
@@ -2034,6 +2134,9 @@ void __hci_req_update_scan(struct hci_request *req)
 	if (mgmt_powering_down(hdev))
 		return;
 
+	if (hdev->scanning_paused)
+		return;
+
 	if (hci_dev_test_flag(hdev, HCI_CONNECTABLE) ||
 	    disconnected_whitelist_entries(hdev))
 		scan = SCAN_PAGE;
-- 
2.25.1.481.gfbce0eb801-goog

[RFC PATCH v5 3/5] Bluetooth: Handle LE devices during suspend

[Abhishek Pandit-Subedi]

To handle LE devices, we must first disable passive scanning and
disconnect all connected devices. Once that is complete, we update the
whitelist and re-enable scanning

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v5:
* Add wakeable to hci_conn_params and change BT_DBG to bt_dev_dbg

Changes in v4: None
Changes in v3:
* Split LE changes into its own commit

Changes in v2: None

 include/net/bluetooth/hci_core.h |   1 +
 net/bluetooth/hci_request.c      | 166 +++++++++++++++++++++----------
 2 files changed, 113 insertions(+), 54 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 1a4d732bdce6..2d58485d0335 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -607,6 +607,7 @@ struct hci_conn_params {
 
 	struct hci_conn *conn;
 	bool explicit_connect;
+	bool wakeable;
 };
 
 extern struct list_head hci_dev_list;
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index bb52aedc91b7..a234735c04f4 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -34,6 +34,9 @@
 #define HCI_REQ_PEND	  1
 #define HCI_REQ_CANCELED  2
 
+#define LE_SUSPEND_SCAN_WINDOW		0x0012
+#define LE_SUSPEND_SCAN_INTERVAL	0x0060
+
 void hci_req_init(struct hci_request *req, struct hci_dev *hdev)
 {
 	skb_queue_head_init(&req->cmd_q);
@@ -654,6 +657,11 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
 {
 	struct hci_dev *hdev = req->hdev;
 
+	if (hdev->scanning_paused) {
+		bt_dev_dbg(hdev, "Scanning is paused for suspend");
+		return;
+	}
+
 	if (use_ext_scan(hdev)) {
 		struct hci_cp_le_set_ext_scan_enable cp;
 
@@ -670,15 +678,55 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
 	}
 }
 
-static void add_to_white_list(struct hci_request *req,
-			      struct hci_conn_params *params)
+static void del_from_white_list(struct hci_request *req, bdaddr_t *bdaddr,
+				u8 bdaddr_type)
+{
+	struct hci_cp_le_del_from_white_list cp;
+
+	cp.bdaddr_type = bdaddr_type;
+	bacpy(&cp.bdaddr, bdaddr);
+
+	bt_dev_dbg(req->hdev, "Remove %pMR (0x%x) from whitelist", &cp.bdaddr,
+		   cp.bdaddr_type);
+	hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST, sizeof(cp), &cp);
+}
+
+/* Adds connection to white list if needed. On error, returns -1. */
+static int add_to_white_list(struct hci_request *req,
+			     struct hci_conn_params *params, u8 *num_entries,
+			     bool allow_rpa)
 {
 	struct hci_cp_le_add_to_white_list cp;
+	struct hci_dev *hdev = req->hdev;
+
+	/* Already in white list */
+	if (hci_bdaddr_list_lookup(&hdev->le_white_list, &params->addr,
+				   params->addr_type))
+		return 0;
+
+	/* Select filter policy to accept all advertising */
+	if (*num_entries >= hdev->le_white_list_size)
+		return -1;
 
+	/* White list can not be used with RPAs */
+	if (!allow_rpa &&
+	    hci_find_irk_by_addr(hdev, &params->addr, params->addr_type)) {
+		return -1;
+	}
+
+	/* During suspend, only wakeable devices can be in whitelist */
+	if (hdev->suspended && !params->wakeable)
+		return 0;
+
+	*num_entries += 1;
 	cp.bdaddr_type = params->addr_type;
 	bacpy(&cp.bdaddr, &params->addr);
 
+	bt_dev_dbg(hdev, "Add %pMR (0x%x) to whitelist", &cp.bdaddr,
+		   cp.bdaddr_type);
 	hci_req_add(req, HCI_OP_LE_ADD_TO_WHITE_LIST, sizeof(cp), &cp);
+
+	return 0;
 }
 
 static u8 update_white_list(struct hci_request *req)
@@ -686,7 +734,14 @@ static u8 update_white_list(struct hci_request *req)
 	struct hci_dev *hdev = req->hdev;
 	struct hci_conn_params *params;
 	struct bdaddr_list *b;
-	uint8_t white_list_entries = 0;
+	u8 num_entries = 0;
+	bool pend_conn, pend_report;
+	/* We allow whitelisting even with RPAs in suspend. In the worst case,
+	 * we won't be able to wake from devices that use the privacy1.2
+	 * features. Additionally, once we support privacy1.2 and IRK
+	 * offloading, we can update this to also check for those conditions.
+	 */
+	bool allow_rpa = hdev->suspended;
 
 	/* Go through the current white list programmed into the
 	 * controller one by one and check if that address is still
@@ -695,29 +750,28 @@ static u8 update_white_list(struct hci_request *req)
 	 * command to remove it from the controller.
 	 */
 	list_for_each_entry(b, &hdev->le_white_list, list) {
-		/* If the device is neither in pend_le_conns nor
-		 * pend_le_reports then remove it from the whitelist.
+		pend_conn = hci_pend_le_action_lookup(&hdev->pend_le_conns,
+						      &b->bdaddr,
+						      b->bdaddr_type);
+		pend_report = hci_pend_le_action_lookup(&hdev->pend_le_reports,
+							&b->bdaddr,
+							b->bdaddr_type);
+
+		/* If the device is not likely to connect or report,
+		 * remove it from the whitelist.
 		 */
-		if (!hci_pend_le_action_lookup(&hdev->pend_le_conns,
-					       &b->bdaddr, b->bdaddr_type) &&
-		    !hci_pend_le_action_lookup(&hdev->pend_le_reports,
-					       &b->bdaddr, b->bdaddr_type)) {
-			struct hci_cp_le_del_from_white_list cp;
-
-			cp.bdaddr_type = b->bdaddr_type;
-			bacpy(&cp.bdaddr, &b->bdaddr);
-
-			hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST,
-				    sizeof(cp), &cp);
+		if (!pend_conn && !pend_report) {
+			del_from_white_list(req, &b->bdaddr, b->bdaddr_type);
 			continue;
 		}
 
-		if (hci_find_irk_by_addr(hdev, &b->bdaddr, b->bdaddr_type)) {
-			/* White list can not be used with RPAs */
+		/* White list can not be used with RPAs */
+		if (!allow_rpa &&
+		    hci_find_irk_by_addr(hdev, &b->bdaddr, b->bdaddr_type)) {
 			return 0x00;
 		}
 
-		white_list_entries++;
+		num_entries++;
 	}
 
 	/* Since all no longer valid white list entries have been
@@ -731,47 +785,17 @@ static u8 update_white_list(struct hci_request *req)
 	 * white list.
 	 */
 	list_for_each_entry(params, &hdev->pend_le_conns, action) {
-		if (hci_bdaddr_list_lookup(&hdev->le_white_list,
-					   &params->addr, params->addr_type))
-			continue;
-
-		if (white_list_entries >= hdev->le_white_list_size) {
-			/* Select filter policy to accept all advertising */
+		if (add_to_white_list(req, params, &num_entries, allow_rpa))
 			return 0x00;
-		}
-
-		if (hci_find_irk_by_addr(hdev, &params->addr,
-					 params->addr_type)) {
-			/* White list can not be used with RPAs */
-			return 0x00;
-		}
-
-		white_list_entries++;
-		add_to_white_list(req, params);
 	}
 
 	/* After adding all new pending connections, walk through
 	 * the list of pending reports and also add these to the
-	 * white list if there is still space.
+	 * white list if there is still space. Abort if space runs out.
 	 */
 	list_for_each_entry(params, &hdev->pend_le_reports, action) {
-		if (hci_bdaddr_list_lookup(&hdev->le_white_list,
-					   &params->addr, params->addr_type))
-			continue;
-
-		if (white_list_entries >= hdev->le_white_list_size) {
-			/* Select filter policy to accept all advertising */
+		if (add_to_white_list(req, params, &num_entries, allow_rpa))
 			return 0x00;
-		}
-
-		if (hci_find_irk_by_addr(hdev, &params->addr,
-					 params->addr_type)) {
-			/* White list can not be used with RPAs */
-			return 0x00;
-		}
-
-		white_list_entries++;
-		add_to_white_list(req, params);
 	}
 
 	/* Select filter policy to use white list */
@@ -866,6 +890,12 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
 	struct hci_dev *hdev = req->hdev;
 	u8 own_addr_type;
 	u8 filter_policy;
+	u8 window, interval;
+
+	if (hdev->scanning_paused) {
+		bt_dev_dbg(hdev, "Scanning is paused for suspend");
+		return;
+	}
 
 	/* Set require_privacy to false since no SCAN_REQ are send
 	 * during passive scanning. Not using an non-resolvable address
@@ -896,8 +926,17 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
 	    (hdev->le_features[0] & HCI_LE_EXT_SCAN_POLICY))
 		filter_policy |= 0x02;
 
-	hci_req_start_scan(req, LE_SCAN_PASSIVE, hdev->le_scan_interval,
-			   hdev->le_scan_window, own_addr_type, filter_policy);
+	if (hdev->suspended) {
+		window = LE_SUSPEND_SCAN_WINDOW;
+		interval = LE_SUSPEND_SCAN_INTERVAL;
+	} else {
+		window = hdev->le_scan_window;
+		interval = hdev->le_scan_interval;
+	}
+
+	bt_dev_dbg(hdev, "LE passive scan with whitelist = %d", filter_policy);
+	hci_req_start_scan(req, LE_SCAN_PASSIVE, interval, window,
+			   own_addr_type, filter_policy);
 }
 
 static u8 get_adv_instance_scan_rsp_len(struct hci_dev *hdev, u8 instance)
@@ -957,6 +996,18 @@ static void hci_req_set_event_filter(struct hci_request *req)
 	hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan);
 }
 
+static void hci_req_config_le_suspend_scan(struct hci_request *req)
+{
+	/* Can't change params without disabling first */
+	hci_req_add_le_scan_disable(req);
+
+	/* Configure params and enable scanning */
+	hci_req_add_le_passive_scan(req);
+
+	/* Block suspend notifier on response */
+	set_bit(SUSPEND_SCAN_ENABLE, req->hdev->suspend_tasks);
+}
+
 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,
@@ -992,6 +1043,9 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		page_scan = SCAN_DISABLED;
 		hci_req_add(&req, HCI_OP_WRITE_SCAN_ENABLE, 1, &page_scan);
 
+		/* Disable LE passive scan */
+		hci_req_add_le_scan_disable(&req);
+
 		/* Mark task needing completion */
 		set_bit(SUSPEND_SCAN_DISABLE, hdev->suspend_tasks);
 
@@ -1019,6 +1073,8 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		hdev->scanning_paused = false;
 		/* Enable event filter for paired devices */
 		hci_req_set_event_filter(&req);
+		/* Enable passive scan at lower duty cycle */
+		hci_req_config_le_suspend_scan(&req);
 		/* Pause scan changes again. */
 		hdev->scanning_paused = true;
 		hci_req_run(&req, suspend_req_complete);
@@ -1027,6 +1083,8 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		hdev->scanning_paused = false;
 
 		hci_req_clear_event_filter(&req);
+		/* Reset passive/background scanning to normal */
+		hci_req_config_le_suspend_scan(&req);
 		hci_req_run(&req, suspend_req_complete);
 	}
 
-- 
2.25.1.481.gfbce0eb801-goog

[RFC PATCH v5 4/5] Bluetooth: Pause discovery and advertising during suspend

[Abhishek Pandit-Subedi]

To prevent spurious wake ups, we disable any discovery or advertising
when we enter suspend and restore it when we exit suspend. While paused,
we disable any management requests to modify discovery or advertising.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v5:
* Changed BT_DBG to bt_dev_dbg

Changes in v4: None
Changes in v3: None
Changes in v2:
* Refactored pause discovery + advertising into its own patch

 include/net/bluetooth/hci_core.h | 11 ++++++++
 net/bluetooth/hci_request.c      | 43 ++++++++++++++++++++++++++++++++
 net/bluetooth/mgmt.c             | 41 ++++++++++++++++++++++++++++++
 3 files changed, 95 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 2d58485d0335..d4e28773d378 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -91,6 +91,12 @@ struct discovery_state {
 #define SUSPEND_NOTIFIER_TIMEOUT	msecs_to_jiffies(2000) /* 2 seconds */
 
 enum suspend_tasks {
+	SUSPEND_PAUSE_DISCOVERY,
+	SUSPEND_UNPAUSE_DISCOVERY,
+
+	SUSPEND_PAUSE_ADVERTISING,
+	SUSPEND_UNPAUSE_ADVERTISING,
+
 	SUSPEND_SCAN_DISABLE,
 	SUSPEND_SCAN_ENABLE,
 	SUSPEND_DISCONNECTING,
@@ -410,6 +416,11 @@ struct hci_dev {
 
 	struct discovery_state	discovery;
 
+	int			discovery_old_state;
+	bool			discovery_paused;
+	int			advertising_old_state;
+	bool			advertising_paused;
+
 	struct notifier_block	suspend_notifier;
 	struct work_struct	suspend_prepare;
 	enum suspended_state	suspend_state_next;
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index a234735c04f4..9995f3cc1e74 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -1039,6 +1039,28 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		/* Mark device as suspended */
 		hdev->suspended = true;
 
+		/* Pause discovery if not already stopped */
+		old_state = hdev->discovery.state;
+		if (old_state != DISCOVERY_STOPPED) {
+			set_bit(SUSPEND_PAUSE_DISCOVERY, hdev->suspend_tasks);
+			hci_discovery_set_state(hdev, DISCOVERY_STOPPING);
+			queue_work(hdev->req_workqueue, &hdev->discov_update);
+		}
+
+		hdev->discovery_paused = true;
+		hdev->discovery_old_state = old_state;
+
+		/* Stop advertising */
+		old_state = hci_dev_test_flag(hdev, HCI_ADVERTISING);
+		if (old_state) {
+			set_bit(SUSPEND_PAUSE_ADVERTISING, hdev->suspend_tasks);
+			cancel_delayed_work(&hdev->discov_off);
+			queue_delayed_work(hdev->req_workqueue,
+					   &hdev->discov_off, 0);
+		}
+
+		hdev->advertising_paused = true;
+		hdev->advertising_old_state = old_state;
 		/* Disable page scan */
 		page_scan = SCAN_DISABLED;
 		hci_req_add(&req, HCI_OP_WRITE_SCAN_ENABLE, 1, &page_scan);
@@ -1085,6 +1107,27 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
 		hci_req_clear_event_filter(&req);
 		/* Reset passive/background scanning to normal */
 		hci_req_config_le_suspend_scan(&req);
+
+		/* Unpause advertising */
+		hdev->advertising_paused = false;
+		if (hdev->advertising_old_state) {
+			set_bit(SUSPEND_UNPAUSE_ADVERTISING,
+				hdev->suspend_tasks);
+			hci_dev_set_flag(hdev, HCI_ADVERTISING);
+			queue_work(hdev->req_workqueue,
+				   &hdev->discoverable_update);
+			hdev->advertising_old_state = 0;
+		}
+
+		/* Unpause discovery */
+		hdev->discovery_paused = false;
+		if (hdev->discovery_old_state != DISCOVERY_STOPPED &&
+		    hdev->discovery_old_state != DISCOVERY_STOPPING) {
+			set_bit(SUSPEND_UNPAUSE_DISCOVERY, hdev->suspend_tasks);
+			hci_discovery_set_state(hdev, DISCOVERY_STARTING);
+			queue_work(hdev->req_workqueue, &hdev->discov_update);
+		}
+
 		hci_req_run(&req, suspend_req_complete);
 	}
 
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 4da48618b271..047aea280c84 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1390,6 +1390,12 @@ static int set_discoverable(struct sock *sk, struct hci_dev *hdev, void *data,
 		goto failed;
 	}
 
+	if (hdev->advertising_paused) {
+		err = mgmt_cmd_status(sk, hdev->id, MGMT_OP_SET_DISCOVERABLE,
+				      MGMT_STATUS_BUSY);
+		goto failed;
+	}
+
 	if (!hdev_is_powered(hdev)) {
 		bool changed = false;
 
@@ -3929,6 +3935,13 @@ void mgmt_start_discovery_complete(struct hci_dev *hdev, u8 status)
 	}
 
 	hci_dev_unlock(hdev);
+
+	/* Handle suspend notifier */
+	if (test_and_clear_bit(SUSPEND_UNPAUSE_DISCOVERY,
+			       hdev->suspend_tasks)) {
+		bt_dev_dbg(hdev, "Unpaused discovery");
+		wake_up(&hdev->suspend_wait_q);
+	}
 }
 
 static bool discovery_type_is_valid(struct hci_dev *hdev, uint8_t type,
@@ -3990,6 +4003,13 @@ static int start_discovery_internal(struct sock *sk, struct hci_dev *hdev,
 		goto failed;
 	}
 
+	/* Can't start discovery when it is paused */
+	if (hdev->discovery_paused) {
+		err = mgmt_cmd_complete(sk, hdev->id, op, MGMT_STATUS_BUSY,
+					&cp->type, sizeof(cp->type));
+		goto failed;
+	}
+
 	/* Clear the discovery filter first to free any previously
 	 * allocated memory for the UUID list.
 	 */
@@ -4157,6 +4177,12 @@ void mgmt_stop_discovery_complete(struct hci_dev *hdev, u8 status)
 	}
 
 	hci_dev_unlock(hdev);
+
+	/* Handle suspend notifier */
+	if (test_and_clear_bit(SUSPEND_PAUSE_DISCOVERY, hdev->suspend_tasks)) {
+		bt_dev_dbg(hdev, "Paused discovery");
+		wake_up(&hdev->suspend_wait_q);
+	}
 }
 
 static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
@@ -4388,6 +4414,17 @@ static void set_advertising_complete(struct hci_dev *hdev, u8 status,
 	if (match.sk)
 		sock_put(match.sk);
 
+	/* Handle suspend notifier */
+	if (test_and_clear_bit(SUSPEND_PAUSE_ADVERTISING,
+			       hdev->suspend_tasks)) {
+		bt_dev_dbg(hdev, "Paused advertising");
+		wake_up(&hdev->suspend_wait_q);
+	} else if (test_and_clear_bit(SUSPEND_UNPAUSE_ADVERTISING,
+				      hdev->suspend_tasks)) {
+		bt_dev_dbg(hdev, "Unpaused advertising");
+		wake_up(&hdev->suspend_wait_q);
+	}
+
 	/* If "Set Advertising" was just disabled and instance advertising was
 	 * set up earlier, then re-enable multi-instance advertising.
 	 */
@@ -4439,6 +4476,10 @@ static int set_advertising(struct sock *sk, struct hci_dev *hdev, void *data,
 		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_SET_ADVERTISING,
 				       MGMT_STATUS_INVALID_PARAMS);
 
+	if (hdev->advertising_paused)
+		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_SET_ADVERTISING,
+				       MGMT_STATUS_BUSY);
+
 	hci_dev_lock(hdev);
 
 	val = !!cp->val;
-- 
2.25.1.481.gfbce0eb801-goog

[RFC PATCH v5 5/5] Bluetooth: Add mgmt op set_wake_capable

[Abhishek Pandit-Subedi]

When the system is suspended, only some connected Bluetooth devices
cause user input that should wake the system (mostly HID devices). Add
a list to keep track of devices that can wake the system and add
a management API to let userspace tell the kernel whether a device is
wake capable or not. For LE devices, the wakeable property is added to
the connection parameter and can only be modified after calling
add_device.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

Changes in v5:
* Wakeable entries moved to other commits
* Patch moved to end of series

Changes in v4: None
Changes in v3:
* Added wakeable property to le_conn_param
* Use wakeable list for BR/EDR and wakeable property for LE

Changes in v2: None

 include/net/bluetooth/mgmt.h |  7 +++++
 net/bluetooth/mgmt.c         | 51 ++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index f41cd87550dc..17bbdcbeb67e 100644
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -674,6 +674,13 @@ struct mgmt_cp_set_blocked_keys {
 
 #define MGMT_OP_SET_WIDEBAND_SPEECH	0x0047
 
+#define MGMT_OP_SET_WAKE_CAPABLE	0x0048
+#define MGMT_SET_WAKE_CAPABLE_SIZE	8
+struct mgmt_cp_set_wake_capable {
+	struct mgmt_addr_info addr;
+	u8 wake_capable;
+} __packed;
+
 #define MGMT_EV_CMD_COMPLETE		0x0001
 struct mgmt_ev_cmd_complete {
 	__le16	opcode;
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 047aea280c84..ab9685e87b84 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -108,6 +108,7 @@ static const u16 mgmt_commands[] = {
 	MGMT_OP_SET_APPEARANCE,
 	MGMT_OP_SET_BLOCKED_KEYS,
 	MGMT_OP_SET_WIDEBAND_SPEECH,
+	MGMT_OP_SET_WAKE_CAPABLE,
 };
 
 static const u16 mgmt_events[] = {
@@ -4768,6 +4769,48 @@ static int set_fast_connectable(struct sock *sk, struct hci_dev *hdev,
 	return err;
 }
 
+static int set_wake_capable(struct sock *sk, struct hci_dev *hdev, void *data,
+			    u16 len)
+{
+	struct mgmt_cp_set_wake_capable *cp = data;
+	struct hci_conn_params *params;
+	int err;
+	u8 status = MGMT_STATUS_FAILED;
+	u8 addr_type = cp->addr.type == BDADDR_BREDR ?
+			       cp->addr.type :
+			       le_addr_type(cp->addr.type);
+
+	bt_dev_dbg(hdev, "Set wake capable %pMR (type 0x%x) = 0x%x\n",
+		   &cp->addr.bdaddr, addr_type, cp->wake_capable);
+
+	if (cp->addr.type == BDADDR_BREDR) {
+		if (cp->wake_capable)
+			err = hci_bdaddr_list_add(&hdev->wakeable,
+						  &cp->addr.bdaddr, addr_type);
+		else
+			err = hci_bdaddr_list_del(&hdev->wakeable,
+						  &cp->addr.bdaddr, addr_type);
+
+		if (!err || err == -EEXIST || err == -ENOENT)
+			status = MGMT_STATUS_SUCCESS;
+
+		goto done;
+	}
+
+	/* Add wakeable param to le connection parameters */
+	params = hci_conn_params_lookup(hdev, &cp->addr.bdaddr, addr_type);
+	if (params) {
+		params->wakeable = cp->wake_capable;
+		status = MGMT_STATUS_SUCCESS;
+	}
+
+done:
+	err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_SET_WAKE_CAPABLE, status,
+				cp, sizeof(*cp));
+
+	return err;
+}
+
 static void set_bredr_complete(struct hci_dev *hdev, u8 status, u16 opcode)
 {
 	struct mgmt_pending_cmd *cmd;
@@ -5896,6 +5939,13 @@ static int remove_device(struct sock *sk, struct hci_dev *hdev,
 			err = hci_bdaddr_list_del(&hdev->whitelist,
 						  &cp->addr.bdaddr,
 						  cp->addr.type);
+
+			/* Don't check result since it either succeeds or device
+			 * wasn't there (not wakeable or invalid params as
+			 * covered by deleting from whitelist).
+			 */
+			hci_bdaddr_list_del(&hdev->wakeable, &cp->addr.bdaddr,
+					    cp->addr.type);
 			if (err) {
 				err = mgmt_cmd_complete(sk, hdev->id,
 							MGMT_OP_REMOVE_DEVICE,
@@ -7096,6 +7146,7 @@ static const struct hci_mgmt_handler mgmt_handlers[] = {
 	{ set_blocked_keys,	   MGMT_OP_SET_BLOCKED_KEYS_SIZE,
 						HCI_MGMT_VAR_LEN },
 	{ set_wideband_speech,	   MGMT_SETTING_SIZE },
+	{ set_wake_capable,	   MGMT_SET_WAKE_CAPABLE_SIZE },
 };
 
 void mgmt_index_added(struct hci_dev *hdev)
-- 
2.25.1.481.gfbce0eb801-goog

Re: [RFC PATCH v5 0/5] Bluetooth: Handle system suspend gracefully

[Marcel Holtmann]

Hi Abhishek,

> This patch series prepares the Bluetooth controller for system suspend
> by disconnecting all devices and preparing the event filter and LE
> whitelist with devices that can wake the system from suspend.
> 
> The main motivation for doing this is so we can enable Bluetooth as
> a wake up source during suspend without it being noisy. Bluetooth should
> wake the system when a HID device receives user input but otherwise not
> send any events to the host.
> 
> This patch series was tested on several Chromebooks with both btusb and
> hci_serdev on kernel 4.19. The set of tests was basically the following:
> * Reconnects after suspend succeed
> * HID devices can wake the system from suspend (needs some related bluez
>  changes to call the Set Wake Capable management command)
> * System properly pauses and unpauses discovery + advertising around
>  suspend
> * System does not wake from any events from non wakeable devices
> 
> Series 2 has refactored the change into multiple smaller commits as
> requested. I tried to simplify some of the whitelist filtering edge
> cases but unfortunately it remains quite complex.
> 
> Series 3 has refactored it further and should have resolved the
> whitelisting complexity in series 2.
> 
> Series 4 adds a fix to check for powered down and powering down adapters.
> 
> Series 5 moves set_wake_capable to the last patch in the series and
> changes BT_DBG to bt_dev_dbg.
> 
> Please review and provide any feedback.

so I was planning to apply patches 1-4. The only thing that I noticed was that patch 2 introduces the following warning.

  CC      net/bluetooth/hci_request.o
net/bluetooth/hci_request.c: In function ‘hci_req_prepare_suspend’:
net/bluetooth/hci_request.c:973:6: warning: unused variable ‘old_state’ [-Wunused-variable]
  973 |  int old_state;
      |      ^~~~~~~~~

I think this variable should only be introduced in patch 4. Are you able to respin this series so that the variable moves to patch 4. If not, I can try to fix this myself.

Regards

Marcel

Re: [RFC PATCH v5 0/5] Bluetooth: Handle system suspend gracefully

[Abhishek Pandit-Subedi]

Sure -- patch incoming in a few minutes.

On Wed, Mar 11, 2020 at 8:03 AM Marcel Holtmann <marcel@holtmann.org> wrote:
>
> Hi Abhishek,
>
> > This patch series prepares the Bluetooth controller for system suspend
> > by disconnecting all devices and preparing the event filter and LE
> > whitelist with devices that can wake the system from suspend.
> >
> > The main motivation for doing this is so we can enable Bluetooth as
> > a wake up source during suspend without it being noisy. Bluetooth should
> > wake the system when a HID device receives user input but otherwise not
> > send any events to the host.
> >
> > This patch series was tested on several Chromebooks with both btusb and
> > hci_serdev on kernel 4.19. The set of tests was basically the following:
> > * Reconnects after suspend succeed
> > * HID devices can wake the system from suspend (needs some related bluez
> >  changes to call the Set Wake Capable management command)
> > * System properly pauses and unpauses discovery + advertising around
> >  suspend
> > * System does not wake from any events from non wakeable devices
> >
> > Series 2 has refactored the change into multiple smaller commits as
> > requested. I tried to simplify some of the whitelist filtering edge
> > cases but unfortunately it remains quite complex.
> >
> > Series 3 has refactored it further and should have resolved the
> > whitelisting complexity in series 2.
> >
> > Series 4 adds a fix to check for powered down and powering down adapters.
> >
> > Series 5 moves set_wake_capable to the last patch in the series and
> > changes BT_DBG to bt_dev_dbg.
> >
> > Please review and provide any feedback.
>
> so I was planning to apply patches 1-4. The only thing that I noticed was that patch 2 introduces the following warning.
>
>   CC      net/bluetooth/hci_request.o
> net/bluetooth/hci_request.c: In function ‘hci_req_prepare_suspend’:
> net/bluetooth/hci_request.c:973:6: warning: unused variable ‘old_state’ [-Wunused-variable]
>   973 |  int old_state;
>       |      ^~~~~~~~~
>
> I think this variable should only be introduced in patch 4. Are you able to respin this series so that the variable moves to patch 4. If not, I can try to fix this myself.
>
> Regards
>
> Marcel
>

Re: [RFC PATCH v5 0/5] Bluetooth: Handle system suspend gracefully

[Abhishek Pandit-Subedi]

Sure -- patch incoming in a few minutes.

On Wed, Mar 11, 2020 at 8:03 AM Marcel Holtmann <marcel@holtmann.org> wrote:
>
> Hi Abhishek,
>
> > This patch series prepares the Bluetooth controller for system suspend
> > by disconnecting all devices and preparing the event filter and LE
> > whitelist with devices that can wake the system from suspend.
> >
> > The main motivation for doing this is so we can enable Bluetooth as
> > a wake up source during suspend without it being noisy. Bluetooth should
> > wake the system when a HID device receives user input but otherwise not
> > send any events to the host.
> >
> > This patch series was tested on several Chromebooks with both btusb and
> > hci_serdev on kernel 4.19. The set of tests was basically the following:
> > * Reconnects after suspend succeed
> > * HID devices can wake the system from suspend (needs some related bluez
> >  changes to call the Set Wake Capable management command)
> > * System properly pauses and unpauses discovery + advertising around
> >  suspend
> > * System does not wake from any events from non wakeable devices
> >
> > Series 2 has refactored the change into multiple smaller commits as
> > requested. I tried to simplify some of the whitelist filtering edge
> > cases but unfortunately it remains quite complex.
> >
> > Series 3 has refactored it further and should have resolved the
> > whitelisting complexity in series 2.
> >
> > Series 4 adds a fix to check for powered down and powering down adapters.
> >
> > Series 5 moves set_wake_capable to the last patch in the series and
> > changes BT_DBG to bt_dev_dbg.
> >
> > Please review and provide any feedback.
>
> so I was planning to apply patches 1-4. The only thing that I noticed was that patch 2 introduces the following warning.
>
>   CC      net/bluetooth/hci_request.o
> net/bluetooth/hci_request.c: In function ‘hci_req_prepare_suspend’:
> net/bluetooth/hci_request.c:973:6: warning: unused variable ‘old_state’ [-Wunused-variable]
>   973 |  int old_state;
>       |      ^~~~~~~~~
>
> I think this variable should only be introduced in patch 4. Are you able to respin this series so that the variable moves to patch 4. If not, I can try to fix this myself.
>
> Regards
>
> Marcel
>