Bluetooth: Add le_scan_restart work for LE scan restarting
Currently there is no way to restart le scan, and it's needed in
service scan method. The way it work: it disable, and then enable le
scan on controller.
During the restart, we must remember when the scan was started, and
it's duration, to later re-schedule the le_scan_disable work, that was
stopped during the stop scan phase.
Signed-off-by: Jakub Pawlowski <jpawlowski@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index a37e10f..d3a232b 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -79,6 +79,8 @@
s8 rssi;
u16 uuid_count;
u8 (*uuids)[16];
+ unsigned long scan_start;
+ unsigned long scan_duration;
};
struct hci_conn_hash {
@@ -354,6 +356,7 @@
unsigned long dev_flags;
struct delayed_work le_scan_disable;
+ struct delayed_work le_scan_restart;
__s8 adv_tx_power;
__u8 adv_data[HCI_MAX_AD_LENGTH];
@@ -531,6 +534,8 @@
hdev->discovery.uuid_count = 0;
kfree(hdev->discovery.uuids);
hdev->discovery.uuids = NULL;
+ hdev->discovery.scan_start = 0;
+ hdev->discovery.scan_duration = 0;
}
bool hci_discovery_active(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index f045c06..3322d3f 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1617,6 +1617,7 @@
cancel_delayed_work(&hdev->service_cache);
cancel_delayed_work_sync(&hdev->le_scan_disable);
+ cancel_delayed_work_sync(&hdev->le_scan_restart);
if (test_bit(HCI_MGMT, &hdev->dev_flags))
cancel_delayed_work_sync(&hdev->rpa_expired);
@@ -2830,6 +2831,8 @@
return;
}
+ hdev->discovery.scan_start = 0;
+
switch (hdev->discovery.type) {
case DISCOV_TYPE_LE:
hci_dev_lock(hdev);
@@ -2869,6 +2872,8 @@
BT_DBG("%s", hdev->name);
+ cancel_delayed_work_sync(&hdev->le_scan_restart);
+
hci_req_init(&req, hdev);
hci_req_add_le_scan_disable(&req);
@@ -2878,6 +2883,74 @@
BT_ERR("Disable LE scanning request failed: err %d", err);
}
+static void le_scan_restart_work_complete(struct hci_dev *hdev, u8 status,
+ u16 opcode)
+{
+ unsigned long timeout, duration, scan_start, now;
+
+ BT_DBG("%s", hdev->name);
+
+ if (status) {
+ BT_ERR("Failed to restart LE scan: status %d", status);
+ return;
+ }
+
+ if (!test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks) ||
+ !hdev->discovery.scan_start)
+ return;
+
+ /* When the scan was started, hdev->le_scan_disable has been queued
+ * after duration from scan_start. During scan restart this job
+ * has been canceled, and we need to queue it again after proper
+ * timeout, to make sure that scan does not run indefinitely.
+ */
+ duration = hdev->discovery.scan_duration;
+ scan_start = hdev->discovery.scan_start;
+ now = jiffies;
+ if (now - scan_start <= duration) {
+ int elapsed;
+
+ if (now >= scan_start)
+ elapsed = now - scan_start;
+ else
+ elapsed = ULONG_MAX - scan_start + now;
+
+ timeout = duration - elapsed;
+ } else {
+ timeout = 0;
+ }
+ queue_delayed_work(hdev->workqueue,
+ &hdev->le_scan_disable, timeout);
+}
+
+static void le_scan_restart_work(struct work_struct *work)
+{
+ struct hci_dev *hdev = container_of(work, struct hci_dev,
+ le_scan_restart.work);
+ struct hci_request req;
+ struct hci_cp_le_set_scan_enable cp;
+ int err;
+
+ BT_DBG("%s", hdev->name);
+
+ /* If controller is not scanning we are done. */
+ if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
+ return;
+
+ hci_req_init(&req, hdev);
+
+ hci_req_add_le_scan_disable(&req);
+
+ memset(&cp, 0, sizeof(cp));
+ cp.enable = LE_SCAN_ENABLE;
+ cp.filter_dup = LE_SCAN_FILTER_DUP_ENABLE;
+ hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
+
+ err = hci_req_run(&req, le_scan_restart_work_complete);
+ if (err)
+ BT_ERR("Restart LE scan request failed: err %d", err);
+}
+
/* Copy the Identity Address of the controller.
*
* If the controller has a public BD_ADDR, then by default use that one.
@@ -2974,6 +3047,7 @@
INIT_DELAYED_WORK(&hdev->power_off, hci_power_off);
INIT_DELAYED_WORK(&hdev->discov_off, hci_discov_off);
INIT_DELAYED_WORK(&hdev->le_scan_disable, le_scan_disable_work);
+ INIT_DELAYED_WORK(&hdev->le_scan_restart, le_scan_restart_work);
skb_queue_head_init(&hdev->rx_q);
skb_queue_head_init(&hdev->cmd_q);
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index ba3b4a5..8c2520a 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -3896,6 +3896,9 @@
hci_discovery_set_state(hdev, DISCOVERY_FINDING);
+ /* If the scan involves LE scan, pick proper timeout to schedule
+ * hdev->le_scan_disable that will stop it.
+ */
switch (hdev->discovery.type) {
case DISCOV_TYPE_LE:
timeout = msecs_to_jiffies(DISCOV_LE_TIMEOUT);
@@ -3912,9 +3915,23 @@
break;
}
- if (timeout)
+ if (timeout) {
+ /* When service discovery is used and the controller has
+ * a strict duplicate filter, it is important to remember
+ * the start and duration of the scan. This is required
+ * for restarting scanning during the discovery phase.
+ */
+ if (test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER,
+ &hdev->quirks) &&
+ (hdev->discovery.uuid_count > 0 ||
+ hdev->discovery.rssi != HCI_RSSI_INVALID)) {
+ hdev->discovery.scan_start = jiffies;
+ hdev->discovery.scan_duration = timeout;
+ }
+
queue_delayed_work(hdev->workqueue,
&hdev->le_scan_disable, timeout);
+ }
unlock:
hci_dev_unlock(hdev);