Bluetooth: Add simultaneous dual mode scan

When doing scan through mgmt api, some controllers can do both le and
classic scan at same time. They can be distinguished by
HCI_QUIRK_SIMULTANEOUS_DISCOVERY set.

This patch enables them to use this feature when doing dual mode scan.
Instead of doing le, then classic scan, both scans are run at once.

Signed-off-by: Jakub Pawlowski <jpawlowski@google.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

3 files changed, 70 insertions, 10 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 750d3445f2d2..773f2164d9a1 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2902,12 +2902,26 @@ static void le_scan_disable_work_complete(struct hci_dev *hdev, u8 status,
 
                 hci_dev_lock(hdev);
 
-                hci_inquiry_cache_flush(hdev);
+                if (test_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY,
+                             &hdev->quirks)) {
+                        /* If we were running LE only scan, change discovery
+                         * state. If we were running both LE and BR/EDR inquiry
+                         * simultaneously, and BR/EDR inquiry is already
+                         * finished, stop discovery, otherwise BR/EDR inquiry
+                         * will stop discovery when finished.
+                         */
+                        if (!test_bit(HCI_INQUIRY, &hdev->flags))
+                                hci_discovery_set_state(hdev,
+                                                        DISCOVERY_STOPPED);
+                } else {
+                        hci_inquiry_cache_flush(hdev);
 
-                err = hci_req_run(&req, inquiry_complete);
-                if (err) {
-                        BT_ERR("Inquiry request failed: err %d", err);
-                        hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
+                        err = hci_req_run(&req, inquiry_complete);
+                        if (err) {
+                                BT_ERR("Inquiry request failed: err %d", err);
+                                hci_discovery_set_state(hdev,
+                                                        DISCOVERY_STOPPED);
+                        }
                 }
 
                 hci_dev_unlock(hdev);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d800f0c5aa21..62f92a508961 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2126,7 +2126,16 @@ static void hci_inquiry_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
                 goto unlock;
 
         if (list_empty(&discov->resolve)) {
-                hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
+                /* When BR/EDR inquiry is active and no LE scanning is in
+                 * progress, then change discovery state to indicate completion.
+                 *
+                 * When running LE scanning and BR/EDR inquiry simultaneously
+                 * and the LE scan already finished, then change the discovery
+                 * state to indicate completion.
+                 */
+                if (!hci_dev_test_flag(hdev, HCI_LE_SCAN) ||
+                    !test_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks))
+                        hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
                 goto unlock;
         }
 
@@ -2135,7 +2144,16 @@ static void hci_inquiry_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
                 e->name_state = NAME_PENDING;
                 hci_discovery_set_state(hdev, DISCOVERY_RESOLVING);
         } else {
-                hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
+                /* When BR/EDR inquiry is active and no LE scanning is in
+                 * progress, then change discovery state to indicate completion.
+                 *
+                 * When running LE scanning and BR/EDR inquiry simultaneously
+                 * and the LE scan already finished, then change the discovery
+                 * state to indicate completion.
+                 */
+                if (!hci_dev_test_flag(hdev, HCI_LE_SCAN) ||
+                    !test_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks))
+                        hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
         }
 
 unlock:
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 5a4b9d5a224f..7bcdf61afe11 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1408,9 +1408,10 @@ static bool hci_stop_discovery(struct hci_request *req)
 
         switch (hdev->discovery.state) {
         case DISCOVERY_FINDING:
-                if (test_bit(HCI_INQUIRY, &hdev->flags)) {
+                if (test_bit(HCI_INQUIRY, &hdev->flags))
                         hci_req_add(req, HCI_OP_INQUIRY_CANCEL, 0, NULL);
-                } else {
+
+                if (hci_dev_test_flag(hdev, HCI_LE_SCAN)) {
                         cancel_delayed_work(&hdev->le_scan_disable);
                         hci_req_add_le_scan_disable(req);
                 }
@@ -4019,6 +4020,22 @@ static bool trigger_discovery(struct hci_request *req, u8 *status)
                 break;
 
         case DISCOV_TYPE_INTERLEAVED:
+                if (test_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY,
+                             &hdev->quirks)) {
+                        /* During simultaneous discovery, we double LE scan
+                         * interval. We must leave some time for the controller
+                         * to do BR/EDR inquiry.
+                         */
+                        if (!trigger_le_scan(req, DISCOV_LE_SCAN_INT * 2,
+                                             status))
+                                return false;
+
+                        if (!trigger_bredr_inquiry(req, status))
+                                return false;
+
+                        return true;
+                }
+
                 if (!hci_dev_test_flag(hdev, HCI_BREDR_ENABLED)) {
                         *status = MGMT_STATUS_NOT_SUPPORTED;
                         return false;
@@ -4072,7 +4089,18 @@ static void start_discovery_complete(struct hci_dev *hdev, u8 status,
                 timeout = msecs_to_jiffies(DISCOV_LE_TIMEOUT);
                 break;
         case DISCOV_TYPE_INTERLEAVED:
-                timeout = msecs_to_jiffies(hdev->discov_interleaved_timeout);
+                 /* When running simultaneous discovery, the LE scanning time
+                 * should occupy the whole discovery time sine BR/EDR inquiry
+                 * and LE scanning are scheduled by the controller.
+                 *
+                 * For interleaving discovery in comparison, BR/EDR inquiry
+                 * and LE scanning are done sequentially with separate
+                 * timeouts.
+                 */
+                if (test_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks))
+                        timeout = msecs_to_jiffies(DISCOV_LE_TIMEOUT);
+                else
+                        timeout = msecs_to_jiffies(hdev->discov_interleaved_timeout);
                 break;
         case DISCOV_TYPE_BREDR:
                 timeout = 0;