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Bluetooth: use wait_event API instead of open-coding it

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I've seen timeout errors from HCI commands where it looks like
schedule_timeout() has returned immediately; additional logging for the
error case gives:

	req_status=1 req_result=0 remaining=10000 jiffies

so the device is still in state HCI_REQ_PEND and the value returned by
schedule_timeout() is the same as the original timeout (HCI_INIT_TIMEOUT
on a system with HZ=1000).

Use wait_event_interruptible_timeout() instead of open-coding similar
behaviour which is subject to the spurious failure described above.

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
John Keeping 2018-04-19 16:29:37 +01:00 committed by Marcel Holtmann
parent ee6493462f
commit 67d8cee432
1 changed files with 7 additions and 23 deletions
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30
net/bluetooth/hci_request.c
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@ -122,7 +122,6 @@ void hci_req_sync_cancel(struct hci_dev *hdev, int err)
struct sk_buff *__hci_cmd_sync_ev(struct hci_dev *hdev, u16 opcode, u32 plen,
const void *param, u8 event, u32 timeout)
{
DECLARE_WAITQUEUE(wait, current);
struct hci_request req;
struct sk_buff *skb;
int err = 0;
@ -135,21 +134,14 @@ struct sk_buff *__hci_cmd_sync_ev(struct hci_dev *hdev, u16 opcode, u32 plen,
hdev->req_status = HCI_REQ_PEND;
add_wait_queue(&hdev->req_wait_q, &wait);
set_current_state(TASK_INTERRUPTIBLE);
err = hci_req_run_skb(&req, hci_req_sync_complete);
if (err < 0) {
remove_wait_queue(&hdev->req_wait_q, &wait);
set_current_state(TASK_RUNNING);
if (err < 0)
return ERR_PTR(err);
}
schedule_timeout(timeout);
err = wait_event_interruptible_timeout(hdev->req_wait_q,
hdev->req_status != HCI_REQ_PEND, timeout);
remove_wait_queue(&hdev->req_wait_q, &wait);
if (signal_pending(current))
if (err == -ERESTARTSYS)
return ERR_PTR(-EINTR);
switch (hdev->req_status) {
@ -197,7 +189,6 @@ int __hci_req_sync(struct hci_dev *hdev, int (*func)(struct hci_request *req,
unsigned long opt, u32 timeout, u8 *hci_status)
{
struct hci_request req;
DECLARE_WAITQUEUE(wait, current);
int err = 0;
BT_DBG("%s start", hdev->name);
@ -213,16 +204,10 @@ int __hci_req_sync(struct hci_dev *hdev, int (*func)(struct hci_request *req,
return err;
}
add_wait_queue(&hdev->req_wait_q, &wait);
set_current_state(TASK_INTERRUPTIBLE);
err = hci_req_run_skb(&req, hci_req_sync_complete);
if (err < 0) {
hdev->req_status = 0;
remove_wait_queue(&hdev->req_wait_q, &wait);
set_current_state(TASK_RUNNING);
/* 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
@ -240,11 +225,10 @@ int __hci_req_sync(struct hci_dev *hdev, int (*func)(struct hci_request *req,
return err;
}
schedule_timeout(timeout);
err = wait_event_interruptible_timeout(hdev->req_wait_q,
hdev->req_status != HCI_REQ_PEND, timeout);
remove_wait_queue(&hdev->req_wait_q, &wait);
if (signal_pending(current))
if (err == -ERESTARTSYS)
return -EINTR;
switch (hdev->req_status) {