We are not supposed to block in start_discovery() because
start_discovery code is running in write() syscall context
and this would block the write operation on the mgmt socket.
This way, we cannot directly call hci_do_le_scan() to scan
LE devices in start_discovery(). To overcome this issue a
derefered work (hdev->le_scan) was created so we can properly
call hci_do_le_scan().
The helper function hci_le_scan() simply set LE scan parameters
and queue hdev->le_scan work. The work is queued on system_long_wq
since it can sleep for a few seconds in the worst case (timeout).
Signed-off-by: Andre Guedes <andre.guedes@xxxxxxxxxxxxx>
Acked-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
---
include/net/bluetooth/hci_core.h | 6 ++++++
net/bluetooth/hci_core.c | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 41 insertions(+), 0 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 47111df..0cffb25 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -130,6 +130,7 @@ struct le_scan_params {
u8 type;
u16 interval;
u16 window;
+ int timeout;
};
#define NUM_REASSEMBLY 4
@@ -271,6 +272,9 @@ struct hci_dev {
struct delayed_work le_scan_disable;
+ struct work_struct le_scan;
+ struct le_scan_params le_scan_params;
+
int (*open)(struct hci_dev *hdev);
int (*close)(struct hci_dev *hdev);
int (*flush)(struct hci_dev *hdev);
@@ -1030,5 +1034,7 @@ void hci_le_ltk_neg_reply(struct hci_conn *conn);
int hci_do_inquiry(struct hci_dev *hdev, u8 length);
int hci_cancel_inquiry(struct hci_dev *hdev);
+int hci_le_scan(struct hci_dev *hdev, u8 type, u16 interval, u16 window,
+ int timeout);
#endif /* __HCI_CORE_H */
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2f5d1ae..046add5 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -735,6 +735,8 @@ static int hci_dev_do_close(struct hci_dev *hdev)
{
BT_DBG("%s %p", hdev->name, hdev);
+ cancel_work_sync(&hdev->le_scan);
+
hci_req_cancel(hdev, ENODEV);
hci_req_lock(hdev);
@@ -1650,6 +1652,37 @@ static void le_scan_disable_work(struct work_struct *work)
hci_send_cmd(hdev, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
}
+static void le_scan_work(struct work_struct *work)
+{
+ struct hci_dev *hdev = container_of(work, struct hci_dev, le_scan);
+ struct le_scan_params *param = &hdev->le_scan_params;
+
+ BT_DBG("%s", hdev->name);
+
+ hci_do_le_scan(hdev, param->type, param->interval,
+ param->window, param->timeout);
+}
+
+int hci_le_scan(struct hci_dev *hdev, u8 type, u16 interval, u16 window,
+ int timeout)
+{
+ struct le_scan_params *param = &hdev->le_scan_params;
+
+ BT_DBG("%s", hdev->name);
+
+ if (work_busy(&hdev->le_scan))
+ return -EINPROGRESS;
+
+ param->type = type;
+ param->interval = interval;
+ param->window = window;
+ param->timeout = timeout;
+
+ queue_work(system_long_wq, &hdev->le_scan);
+
+ return 0;
+}
+
/* Register HCI device */
int hci_register_dev(struct hci_dev *hdev)
{
@@ -1735,6 +1768,8 @@ int hci_register_dev(struct hci_dev *hdev)
atomic_set(&hdev->promisc, 0);
+ INIT_WORK(&hdev->le_scan, le_scan_work);
+
INIT_DELAYED_WORK(&hdev->le_scan_disable, le_scan_disable_work);
write_unlock(&hci_dev_list_lock);
--
1.7.9
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
