Bluetooth: Fix hci_sync missing wakeup interrupt

__hci_cmd_sync_ev(), __hci_req_sync() could miss wake_up_interrupt from
hci_req_sync_complete() because hci_cmd_work() workqueue and its response
could be completed before they are ready to get the signal through
add_wait_queue(), set_current_state(TASK_INTERRUPTIBLE).

Signed-off-by: Chan-yeol Park <chanyeol.park@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 91995f8ab0a0..41b147c36d11 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1147,13 +1147,15 @@ struct sk_buff *__hci_cmd_sync_ev(struct hci_dev *hdev, u16 opcode, u32 plen,
 
         hdev->req_status = HCI_REQ_PEND;
 
-        err = hci_req_run(&req, hci_req_sync_complete);
-        if (err < 0)
-                return ERR_PTR(err);
-
         add_wait_queue(&hdev->req_wait_q, &wait);
         set_current_state(TASK_INTERRUPTIBLE);
 
+        err = hci_req_run(&req, hci_req_sync_complete);
+        if (err < 0) {
+                remove_wait_queue(&hdev->req_wait_q, &wait);
+                return ERR_PTR(err);
+        }
+
         schedule_timeout(timeout);
 
         remove_wait_queue(&hdev->req_wait_q, &wait);
@@ -1211,10 +1213,15 @@ static int __hci_req_sync(struct hci_dev *hdev,
 
         func(&req, opt);
 
+        add_wait_queue(&hdev->req_wait_q, &wait);
+        set_current_state(TASK_INTERRUPTIBLE);
+
         err = hci_req_run(&req, hci_req_sync_complete);
         if (err < 0) {
                 hdev->req_status = 0;
 
+                remove_wait_queue(&hdev->req_wait_q, &wait);
+
                 /* ENODATA means the HCI request command queue is empty.
                  * This can happen when a request with conditionals doesn't
                  * trigger any commands to be sent. This is normal behavior
@@ -1226,9 +1233,6 @@ static int __hci_req_sync(struct hci_dev *hdev,
                 return err;
         }
 
-        add_wait_queue(&hdev->req_wait_q, &wait);
-        set_current_state(TASK_INTERRUPTIBLE);
-
         schedule_timeout(timeout);
 
         remove_wait_queue(&hdev->req_wait_q, &wait);