Hi Marcel,
On Thu, Mar 15, 2012 at 12:26 PM, Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote:
> Hi Andre,
>
>> This patch adds to hci_core the hci_cancel_le_scan function which
>> should be used to cancel an ongoing LE scan.
>>
>> Signed-off-by: Andre Guedes <andre.guedes@xxxxxxxxxxxxx>
>> ---
>> include/net/bluetooth/hci_core.h | 1 +
>> net/bluetooth/hci_core.c | 21 +++++++++++++++++++++
>> 2 files changed, 22 insertions(+)
>>
>> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
>> index daefaac..87bca3e 100644
>> --- a/include/net/bluetooth/hci_core.h
>> +++ b/include/net/bluetooth/hci_core.h
>> @@ -1071,5 +1071,6 @@ 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);
>> +int hci_cancel_le_scan(struct hci_dev *hdev);
>>
>> #endif /* __HCI_CORE_H */
>> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
>> index 59ec99e..0320a02 100644
>> --- a/net/bluetooth/hci_core.c
>> +++ b/net/bluetooth/hci_core.c
>> @@ -1667,6 +1667,27 @@ static int hci_do_le_scan(struct hci_dev *hdev, u8 type, u16 interval,
>> return 0;
>> }
>>
>> +int hci_cancel_le_scan(struct hci_dev *hdev)
>> +{
>> + bool canceled;
>> +
>> + BT_DBG("%s", hdev->name);
>> +
>> + if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
>> + return -EALREADY;
>> +
>> + canceled = cancel_delayed_work(&hdev->le_scan_disable);
>
> why are we using the canceled variable here? Seems pointless.
Because le_scan_disable work may be running when cancel_delayed_work
returns (canceled == 0). If le_scan_disable work is running, we should
not send HCI_OP_LE_SET_SCAN_ENABLE command since le_scan_disable work
already sends it.
This way we avoid sending two HCI_OP_LE_SET_SCAN_ENABLE commands when
this race condition occurs.
BR,
Andre
--
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
