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Date:   Fri, 17 Jan 2020 13:27:05 -0800
From:   Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
To:     marcel@...tmann.org, luiz.dentz@...il.com, alainm@...omium.org
Cc:     linux-bluetooth@...r.kernel.org,
        chromeos-bluetooth-upstreaming@...omium.org,
        Abhishek Pandit-Subedi <abhishekpandit@...omium.org>,
        "David S. Miller" <davem@...emloft.net>,
        Johan Hedberg <johan.hedberg@...il.com>,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [RFC PATCH 2/2] Bluetooth: Handle PM_SUSPEND_PREPARE and PM_POST_SUSPEND

Register for PM_SUSPEND_PREPARE and PM_POST_SUSPEND to make sure the
Bluetooth controller is prepared correctly for suspend/resume. The
suspend notifier will wait for all tasks to complete before returning.

At a high level, we do the following when entering suspend:
- Pause any active discovery
- Pause any active advertising
- Set the event filter with addresses of wake capable Classic devices
  and enable Page Scan
- Update the LE whitelist to only include devices that can wake the
  system, update the scan parameters and enable passive scanning.
- Disconnect all devices with a POWER_DOWN reason

On resume, it reverses the above operations:
- Clear event filters and restore page scan
- Restore LE whitelist and restore passive scan
- If advertising was active before suspend, re-enable it
- If discovery was active before suspend, re-enable it

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

 include/net/bluetooth/hci.h      |  30 +++-
 include/net/bluetooth/hci_core.h |  45 +++++
 net/bluetooth/hci_core.c         |  70 ++++++++
 net/bluetooth/hci_event.c        |  24 ++-
 net/bluetooth/hci_request.c      | 297 ++++++++++++++++++++++++++++---
 net/bluetooth/hci_request.h      |   4 +-
 net/bluetooth/mgmt.c             |  52 +++++-
 7 files changed, 486 insertions(+), 36 deletions(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 6293bdd7d862..3c85c556e59a 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -932,10 +932,31 @@ struct hci_cp_sniff_subrate {
 #define HCI_OP_RESET			0x0c03
 
 #define HCI_OP_SET_EVENT_FLT		0x0c05
-struct hci_cp_set_event_flt {
+#define HCI_SET_EVENT_FLT_SIZE		9
+struct hci_cp_set_event_filter {
 	__u8     flt_type;
 	__u8     cond_type;
-	__u8     condition[0];
+	union {
+		union {
+			struct {
+				__u8 val[3];
+				__u8 mask[3];
+			} __packed dev_class;
+			bdaddr_t addr;
+		} inq;
+		union {
+			__u8 auto_accept_any;
+			struct {
+				__u8 val[3];
+				__u8 mask[3];
+				__u8 auto_accept;
+			} __packed dev_class;
+			struct {
+				bdaddr_t bdaddr;
+				__u8 auto_accept;
+			} __packed addr;
+		} conn;
+	} cond;
 } __packed;
 
 /* Filter types */
@@ -949,8 +970,9 @@ 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 ce4bebcb0265..963871fca069 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -88,6 +88,49 @@ struct discovery_state {
 	unsigned long		scan_duration;
 };
 
+#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_LE_SET_SCAN_ENABLE,
+	SUSPEND_DISCONNECTING,
+
+	SUSPEND_PREPARE_NOTIFIER,
+	__SUSPEND_NUM_TASKS
+};
+
+enum suspended_state {
+	BT_RUNNING = 0,
+	BT_SUSPENDED,
+};
+
+struct suspend_state {
+	int	discovery_old_state;
+	int	advertising_old_state;
+
+	bool	discovery_paused;
+	bool	advertising_paused;
+
+	int	disconnect_counter;
+
+	/* BREDR: Disallow changing event filters + page scan.
+	 * LE: Disallow changing whitelist, scan params and scan enable.
+	 */
+	bool	freeze_filters;
+
+	DECLARE_BITMAP(tasks, __SUSPEND_NUM_TASKS);
+	wait_queue_head_t	tasks_wait_q;
+
+	struct work_struct	prepare;
+	enum suspended_state	next_state;
+	enum suspended_state	state;
+};
+
 struct hci_conn_hash {
 	struct list_head list;
 	unsigned int     acl_num;
@@ -389,6 +432,8 @@ struct hci_dev {
 	void			*smp_bredr_data;
 
 	struct discovery_state	discovery;
+	struct suspend_state	suspend;
+	struct notifier_block	suspend_notifier;
 	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 7057b9b65173..76bd4f376790 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>
@@ -3241,6 +3243,65 @@ 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.tasks_wait_q,
+				     WAKE_COND, SUSPEND_NOTIFIER_TIMEOUT);
+
+	if (ret == 0) {
+		BT_DBG("Timed out waiting for suspend");
+		for (i = 0; i < __SUSPEND_NUM_TASKS; ++i) {
+			if (test_bit(i, hdev->suspend.tasks))
+				BT_DBG("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.next_state);
+	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 (action == PM_SUSPEND_PREPARE) {
+		hdev->suspend.next_state = 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.next_state = BT_RUNNING;
+		set_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend.tasks);
+		queue_work(hdev->req_workqueue, &hdev->suspend.prepare);
+
+		ret = hci_suspend_wait_event(hdev);
+	}
+
+	return ret ? notifier_from_errno(-EBUSY) : NOTIFY_STOP;
+}
 /* Alloc HCI device */
 struct hci_dev *hci_alloc_dev(void)
 {
@@ -3319,6 +3380,7 @@ 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);
 
@@ -3327,6 +3389,7 @@ 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.tasks_wait_q);
 
 	INIT_DELAYED_WORK(&hdev->cmd_timer, hci_cmd_timeout);
 
@@ -3438,6 +3501,11 @@ 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;
@@ -3471,6 +3539,8 @@ 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_event.c b/net/bluetooth/hci_event.c
index 6ddc4a74a5e4..623eca68afdd 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2474,6 +2474,7 @@ 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);
@@ -2482,14 +2483,25 @@ 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) {
-		if (ev->link_type != SCO_LINK)
-			goto unlock;
+		ie = hci_inquiry_cache_lookup(hdev, &ev->bdaddr);
+		if (ie) {
+			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;
+			}
+		} else {
+			if (ev->link_type != SCO_LINK)
+				goto unlock;
 
-		conn = hci_conn_hash_lookup_ba(hdev, ESCO_LINK, &ev->bdaddr);
-		if (!conn)
-			goto unlock;
+			conn = hci_conn_hash_lookup_ba(hdev, ESCO_LINK,
+						       &ev->bdaddr);
+			if (!conn)
+				goto unlock;
 
-		conn->type = SCO_LINK;
+			conn->type = SCO_LINK;
+		}
 	}
 
 	if (!ev->status) {
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 2a1b64dbf76e..3044d9e1ea2b 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -447,7 +447,7 @@ static void __hci_update_background_scan(struct hci_request *req)
 		if (hci_dev_test_flag(hdev, HCI_LE_SCAN))
 			hci_req_add_le_scan_disable(req);
 
-		hci_req_add_le_passive_scan(req);
+		hci_req_add_le_passive_scan(req, false);
 
 		BT_DBG("%s starting background scanning", hdev->name);
 	}
@@ -654,6 +654,12 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
 {
 	struct hci_dev *hdev = req->hdev;
 
+	/* Early exit if we've frozen filters for suspend*/
+	if (hdev->suspend.freeze_filters) {
+		BT_DBG("Filters are frozen for suspend");
+		return;
+	}
+
 	if (use_ext_scan(hdev)) {
 		struct hci_cp_le_set_ext_scan_enable cp;
 
@@ -681,12 +687,25 @@ static void add_to_white_list(struct hci_request *req,
 	hci_req_add(req, HCI_OP_LE_ADD_TO_WHITE_LIST, sizeof(cp), &cp);
 }
 
-static u8 update_white_list(struct hci_request *req)
+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);
+
+	hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST, sizeof(cp), &cp);
+}
+
+static u8 update_white_list(struct hci_request *req, bool allow_rpa,
+			    bool remove_nonwakeable)
 {
 	struct hci_dev *hdev = req->hdev;
 	struct hci_conn_params *params;
 	struct bdaddr_list *b;
 	uint8_t white_list_entries = 0;
+	bool wakeable;
 
 	/* Go through the current white list programmed into the
 	 * controller one by one and check if that address is still
@@ -695,24 +714,37 @@ 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.
+		wakeable = !!hci_bdaddr_list_lookup(&hdev->wakeable, &b->bdaddr,
+						    b->bdaddr_type);
+
+		/* If the device is not likely to connect or report, remove it
+		 * from the whitelist. Make an exception for wakeable devices if
+		 * we're removing only non-wakeable devices (we want them to
+		 * stay in 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);
+					       &b->bdaddr, b->bdaddr_type) &&
+		    (!wakeable && remove_nonwakeable)) {
+			BT_DBG("Removing %pMR (0x%x) - not pending or wakeable",
+			       &b->bdaddr, b->bdaddr_type);
+			del_from_white_list(req, &b->bdaddr, b->bdaddr_type);
+			continue;
+		}
 
-			hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST,
-				    sizeof(cp), &cp);
+		/* If we're removing non wakeable devices and this whitelist
+		 * entry is not wake capable, we remove it from the whitelist.
+		 */
+		if (remove_nonwakeable && !wakeable) {
+			BT_DBG("Removing %pMR (0x%x) - not wake capable",
+			       &b->bdaddr, b->bdaddr_type);
+			del_from_white_list(req, &b->bdaddr, b->bdaddr_type);
 			continue;
 		}
 
-		if (hci_find_irk_by_addr(hdev, &b->bdaddr, b->bdaddr_type)) {
+		if (!allow_rpa &&
+		    hci_find_irk_by_addr(hdev, &b->bdaddr, b->bdaddr_type)) {
 			/* White list can not be used with RPAs */
 			return 0x00;
 		}
@@ -740,14 +772,20 @@ static u8 update_white_list(struct hci_request *req)
 			return 0x00;
 		}
 
-		if (hci_find_irk_by_addr(hdev, &params->addr,
-					 params->addr_type)) {
+		if (!allow_rpa && hci_find_irk_by_addr(hdev, &params->addr,
+						       params->addr_type)) {
 			/* White list can not be used with RPAs */
 			return 0x00;
 		}
 
+		if (remove_nonwakeable &&
+		    !hci_bdaddr_list_lookup(&hdev->wakeable, &b->bdaddr,
+					    b->bdaddr_type))
+			continue;
+
 		white_list_entries++;
 		add_to_white_list(req, params);
+		BT_DBG("Adding %pMR to whitelist", &params->addr);
 	}
 
 	/* After adding all new pending connections, walk through
@@ -764,14 +802,20 @@ static u8 update_white_list(struct hci_request *req)
 			return 0x00;
 		}
 
-		if (hci_find_irk_by_addr(hdev, &params->addr,
-					 params->addr_type)) {
+		if (!allow_rpa && hci_find_irk_by_addr(hdev, &params->addr,
+						       params->addr_type)) {
 			/* White list can not be used with RPAs */
 			return 0x00;
 		}
 
+		if (remove_nonwakeable &&
+		    !hci_bdaddr_list_lookup(&hdev->wakeable, &b->bdaddr,
+					    b->bdaddr_type))
+			continue;
+
 		white_list_entries++;
 		add_to_white_list(req, params);
+		BT_DBG("Adding %pMR to whitelist", &params->addr);
 	}
 
 	/* Select filter policy to use white list */
@@ -784,7 +828,8 @@ static bool scan_use_rpa(struct hci_dev *hdev)
 }
 
 static void hci_req_start_scan(struct hci_request *req, u8 type, u16 interval,
-			       u16 window, u8 own_addr_type, u8 filter_policy)
+			       u16 window, u8 own_addr_type, u8 filter_policy,
+			       u8 filter_dup)
 {
 	struct hci_dev *hdev = req->hdev;
 
@@ -836,7 +881,7 @@ static void hci_req_start_scan(struct hci_request *req, u8 type, u16 interval,
 
 		memset(&ext_enable_cp, 0, sizeof(ext_enable_cp));
 		ext_enable_cp.enable = LE_SCAN_ENABLE;
-		ext_enable_cp.filter_dup = LE_SCAN_FILTER_DUP_ENABLE;
+		ext_enable_cp.filter_dup = filter_dup;
 
 		hci_req_add(req, HCI_OP_LE_SET_EXT_SCAN_ENABLE,
 			    sizeof(ext_enable_cp), &ext_enable_cp);
@@ -855,17 +900,47 @@ static void hci_req_start_scan(struct hci_request *req, u8 type, u16 interval,
 
 		memset(&enable_cp, 0, sizeof(enable_cp));
 		enable_cp.enable = LE_SCAN_ENABLE;
-		enable_cp.filter_dup = LE_SCAN_FILTER_DUP_ENABLE;
+		enable_cp.filter_dup = filter_dup;
 		hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(enable_cp),
 			    &enable_cp);
 	}
 }
 
-void hci_req_add_le_passive_scan(struct hci_request *req)
+static u16 __hci_get_scan_interval(struct hci_dev *hdev, bool suspending)
+{
+	if (suspending)
+		return 0x0060;
+	else
+		return hdev->le_scan_interval;
+}
+
+static u16 __hci_get_scan_window(struct hci_dev *hdev, bool suspending)
+{
+	if (suspending)
+		return 0x0012;
+	else
+		return hdev->le_scan_window;
+}
+
+void hci_req_add_le_passive_scan(struct hci_request *req, bool suspending)
 {
 	struct hci_dev *hdev = req->hdev;
 	u8 own_addr_type;
 	u8 filter_policy;
+	u8 filter_dup;
+
+	/* 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 = suspending;
+
+	/* Early exit if we've frozen filters for suspend*/
+	if (hdev->suspend.freeze_filters) {
+		BT_DBG("Filters are frozen for suspend");
+		return;
+	}
 
 	/* Set require_privacy to false since no SCAN_REQ are send
 	 * during passive scanning. Not using an non-resolvable address
@@ -881,7 +956,8 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
 	 * happen before enabling scanning. The controller does
 	 * not allow white list modification while scanning.
 	 */
-	filter_policy = update_white_list(req);
+	BT_DBG("Updating white list with suspending = %d", suspending);
+	filter_policy = update_white_list(req, allow_rpa, suspending);
 
 	/* When the controller is using random resolvable addresses and
 	 * with that having LE privacy enabled, then controllers with
@@ -896,8 +972,14 @@ 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);
+	filter_dup = suspending ? LE_SCAN_FILTER_DUP_DISABLE :
+				  LE_SCAN_FILTER_DUP_ENABLE;
+
+	BT_DBG("LE passive scan with whitelist = %d", filter_policy);
+	hci_req_start_scan(req, LE_SCAN_PASSIVE,
+			   __hci_get_scan_interval(hdev, suspending),
+			   __hci_get_scan_window(hdev, suspending),
+			   own_addr_type, filter_policy, filter_dup);
 }
 
 static u8 get_adv_instance_scan_rsp_len(struct hci_dev *hdev, u8 instance)
@@ -918,6 +1000,170 @@ static u8 get_adv_instance_scan_rsp_len(struct hci_dev *hdev, u8 instance)
 	return adv_instance->scan_rsp_len;
 }
 
+static void hci_req_set_event_filter(struct hci_request *req, bool clear)
+{
+	struct bdaddr_list *b;
+	struct hci_cp_set_event_filter f;
+	struct hci_dev *hdev = req->hdev;
+	int filters_updated = 0;
+	u8 scan;
+
+	/* Always clear event filter when starting */
+	memset(&f, 0, sizeof(f));
+	f.flt_type = HCI_FLT_CLEAR_ALL;
+	hci_req_add(req, HCI_OP_SET_EVENT_FLT, 1, &f);
+
+	if (!clear) {
+		list_for_each_entry(b, &hdev->wakeable, list) {
+			if (b->bdaddr_type != BDADDR_BREDR)
+				continue;
+
+			memset(&f, 0, sizeof(f));
+			bacpy(&f.cond.conn.addr.bdaddr, &b->bdaddr);
+			f.flt_type = HCI_FLT_CONN_SETUP;
+			f.cond_type = HCI_CONN_SETUP_ALLOW_BDADDR;
+			f.cond.conn.addr.auto_accept = HCI_CONN_SETUP_AUTO_ON;
+
+			BT_DBG("Adding event filters for %pMR", &b->bdaddr);
+			hci_req_add(req, HCI_OP_SET_EVENT_FLT, sizeof(f), &f);
+
+			filters_updated++;
+		}
+
+		scan = filters_updated ? SCAN_PAGE : SCAN_DISABLED;
+		hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan);
+	} else {
+		/* Restore page scan to normal (i.e. there are disconnected
+		 * devices in the whitelist.
+		 */
+		__hci_req_update_scan(req);
+	}
+}
+
+static void hci_req_enable_le_suspend_scan(struct hci_request *req,
+					   bool suspending)
+{
+	/* 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, suspending);
+
+	/* Block suspend notifier on response */
+	set_bit(SUSPEND_LE_SET_SCAN_ENABLE, req->hdev->suspend.tasks);
+}
+
+static void le_suspend_req_complete(struct hci_dev *hdev, u8 status, u16 opcode)
+{
+	BT_DBG("Request complete opcode=0x%x, status=0x%x", opcode, status);
+
+	/* Expecting LE Set scan to return */
+	if (opcode == HCI_OP_LE_SET_SCAN_ENABLE &&
+	    test_and_clear_bit(SUSPEND_LE_SET_SCAN_ENABLE,
+			       hdev->suspend.tasks)) {
+		wake_up(&hdev->suspend.tasks_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;
+
+	if (next == hdev->suspend.state) {
+		BT_DBG("Same state before and after: %d", next);
+		goto done;
+	}
+
+	hci_req_init(&req, hdev);
+	if (next == BT_SUSPENDED) {
+		/* 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->suspend.discovery_paused = true;
+		hdev->suspend.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->suspend.advertising_paused = true;
+		hdev->suspend.advertising_old_state = old_state;
+
+		/* Enable event filter for existing devices */
+		hci_req_set_event_filter(&req, false);
+
+		/* Enable passive scan at lower duty cycle */
+		hci_req_enable_le_suspend_scan(&req, true);
+
+		hdev->suspend.freeze_filters = true;
+
+		/* Run commands before disconnecting */
+		hci_req_run(&req, le_suspend_req_complete);
+
+		hdev->suspend.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);
+			hdev->suspend.disconnect_counter++;
+		}
+
+		if (hdev->suspend.disconnect_counter > 0) {
+			BT_DBG("Had %d disconnects. Will wait on them",
+			       hdev->suspend.disconnect_counter);
+			set_bit(SUSPEND_DISCONNECTING, hdev->suspend.tasks);
+		}
+	} else {
+		hdev->suspend.freeze_filters = false;
+
+		/* Clear event filter */
+		hci_req_set_event_filter(&req, true);
+
+		/* Reset passive/background scanning to normal */
+		hci_req_enable_le_suspend_scan(&req, false);
+
+		/* Unpause advertising */
+		hdev->suspend.advertising_paused = false;
+		if (hdev->suspend.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->suspend.advertising_old_state = 0;
+		}
+
+		/* Unpause discovery */
+		hdev->suspend.discovery_paused = false;
+		if (hdev->suspend.discovery_old_state != DISCOVERY_STOPPED &&
+		    hdev->suspend.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, le_suspend_req_complete);
+	}
+
+	hdev->suspend.state = next;
+
+done:
+	clear_bit(SUSPEND_PREPARE_NOTIFIER, hdev->suspend.tasks);
+	wake_up(&hdev->suspend.tasks_wait_q);
+}
+
 static u8 get_cur_adv_instance_scan_rsp_len(struct hci_dev *hdev)
 {
 	u8 instance = hdev->cur_adv_instance;
@@ -2015,6 +2261,9 @@ void __hci_req_update_scan(struct hci_request *req)
 	if (mgmt_powering_down(hdev))
 		return;
 
+	if (hdev->suspend.freeze_filters)
+		return;
+
 	if (hci_dev_test_flag(hdev, HCI_CONNECTABLE) ||
 	    disconnected_whitelist_entries(hdev))
 		scan = SCAN_PAGE;
@@ -2538,7 +2787,7 @@ static int active_scan(struct hci_request *req, unsigned long opt)
 		own_addr_type = ADDR_LE_DEV_PUBLIC;
 
 	hci_req_start_scan(req, LE_SCAN_ACTIVE, interval, DISCOV_LE_SCAN_WIN,
-			   own_addr_type, 0);
+			   own_addr_type, 0, LE_SCAN_FILTER_DUP_DISABLE);
 	return 0;
 }
 
diff --git a/net/bluetooth/hci_request.h b/net/bluetooth/hci_request.h
index a7019fbeadd3..f555bb789664 100644
--- a/net/bluetooth/hci_request.h
+++ b/net/bluetooth/hci_request.h
@@ -66,7 +66,9 @@ void __hci_req_update_name(struct hci_request *req);
 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_add_le_passive_scan(struct hci_request *req, bool suspending);
+
+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);
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 95092130f16c..e5bac060c999 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -24,6 +24,7 @@
 
 /* Bluetooth HCI Management interface */
 
+#include <linux/delay.h>
 #include <linux/module.h>
 #include <asm/unaligned.h>
 
@@ -1385,6 +1386,12 @@ static int set_discoverable(struct sock *sk, struct hci_dev *hdev, void *data,
 		goto failed;
 	}
 
+	if (hdev->suspend.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;
 
@@ -3868,6 +3875,13 @@ 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_DBG("Unpaused discovery");
+		wake_up(&hdev->suspend.tasks_wait_q);
+	}
 }
 
 static bool discovery_type_is_valid(struct hci_dev *hdev, uint8_t type,
@@ -3929,6 +3943,13 @@ static int start_discovery_internal(struct sock *sk, struct hci_dev *hdev,
 		goto failed;
 	}
 
+	/* Can't start discovery when it is paused */
+	if (hdev->suspend.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.
 	 */
@@ -4096,6 +4117,12 @@ 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_DBG("Paused discovery");
+		wake_up(&hdev->suspend.tasks_wait_q);
+	}
 }
 
 static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
@@ -4327,6 +4354,17 @@ 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_DBG("Paused advertising");
+		wake_up(&hdev->suspend.tasks_wait_q);
+	} else if (test_and_clear_bit(SUSPEND_UNPAUSE_ADVERTISING,
+				      hdev->suspend.tasks)) {
+		BT_DBG("Unpaused advertising");
+		wake_up(&hdev->suspend.tasks_wait_q);
+	}
+
 	/* If "Set Advertising" was just disabled and instance advertising was
 	 * set up earlier, then re-enable multi-instance advertising.
 	 */
@@ -4378,6 +4416,10 @@ 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->suspend.advertising_paused)
+		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_SET_ADVERTISING,
+				       MGMT_STATUS_BUSY);
+
 	hci_dev_lock(hdev);
 
 	val = !!cp->val;
@@ -4557,7 +4599,7 @@ static int set_scan_params(struct sock *sk, struct hci_dev *hdev,
 		hci_req_init(&req, hdev);
 
 		hci_req_add_le_scan_disable(&req);
-		hci_req_add_le_passive_scan(&req);
+		hci_req_add_le_passive_scan(&req, false);
 
 		hci_req_run(&req, NULL);
 	}
@@ -7453,6 +7495,14 @@ void mgmt_device_disconnected(struct hci_dev *hdev, bdaddr_t *bdaddr,
 
 	mgmt_event(MGMT_EV_DEVICE_DISCONNECTED, hdev, &ev, sizeof(ev), sk);
 
+	if (hdev->suspend.disconnect_counter > 0) {
+		hdev->suspend.disconnect_counter--;
+		if (hdev->suspend.disconnect_counter <= 0) {
+			clear_bit(SUSPEND_DISCONNECTING, hdev->suspend.tasks);
+			wake_up(&hdev->suspend.tasks_wait_q);
+		}
+	}
+
 	if (sk)
 		sock_put(sk);
 
-- 
2.25.0.341.g760bfbb309-goog

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