Commit 67d8cee4 authored by John Keeping's avatar John Keeping Committed by Marcel Holtmann
Browse files

Bluetooth: use wait_event API instead of open-coding it 



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: default avatarJohn Keeping <john@metanate.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent ee649346

net/bluetooth/hci_request.c

+7 −23
Original line number Diff line number Diff line
@@ -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);



	remove_wait_queue(&hdev->req_wait_q, &wait);

	err = wait_event_interruptible_timeout(hdev->req_wait_q,

			hdev->req_status != HCI_REQ_PEND, timeout);



	if (signal_pending(current))

	if (err == -ERESTARTSYS)

		return -EINTR;



	switch (hdev->req_status) {

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