[RFC] Bluetooth : Fix hci_sync miss wakeup interrupt

[박찬열 <chanyeol.park@xxxxxxxxxxx>]

__hci_cmd_sync_ev(), __hci_req_sync() could miss wake_up_interrupt from
hci_req_sync_complete() because hci_cmd_work() workquee and its reponse
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@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
 net/bluetooth/hci_core.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index cb05d7f..c008f1f 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);
--
1.9.1 
       

  

         
  
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