[RFC PATCH v3 3/5] Bluetooth: Handle BR/EDR devices during suspend
From: Abhishek Pandit-Subedi
Date: Mon Feb 24 2020 - 19:01:22 EST
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@xxxxxxxxxxxx>
---
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 | 9 ++-
net/bluetooth/hci_core.c | 21 ++++++-
net/bluetooth/hci_event.c | 24 ++++++++
net/bluetooth/hci_request.c | 101 +++++++++++++++++++++++++++++++
5 files changed, 162 insertions(+), 10 deletions(-)
diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 6293bdd7d862..720d8e633f7e 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -932,10 +932,14 @@ 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[0];
+#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 */
@@ -949,8 +953,9 @@ 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 bc9620e5b65b..2723a608183e 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -91,13 +91,18 @@ 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_PREPARE_NOTIFIER,
__SUSPEND_NUM_TASKS
};
enum suspended_state {
BT_RUNNING = 0,
- BT_SUSPENDED,
+ BT_SUSPEND_DISCONNECT,
+ BT_SUSPEND_COMPLETE,
};
struct hci_conn_hash {
@@ -406,6 +411,8 @@ 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);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 6ca0aa8d30dd..66b5dbbe8ea0 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3287,16 +3287,31 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action,
int ret = 0;
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);
}
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 591e7477e925..e3c36230f705 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);
@@ -2482,6 +2483,21 @@ 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;
@@ -2743,6 +2759,14 @@ 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 08908469c043..4d67b1d08608 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -918,12 +918,62 @@ 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_DBG("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_DBG("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_DBG("Same state before and after: %d", next);
@@ -931,6 +981,54 @@ 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_DBG("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 +2132,9 @@ 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;
--
2.25.0.265.gbab2e86ba0-goog