Hi Timo,
>> Since the event handling is done within a workqueue, the notify
>> callback can now sleep. So no need to trigger a separate workqueue
>> from within the Bluetooth USB driver.
>>
>> This should give a little bit better latency with the SCO packet
>> processing since the ISOC altsetting is correct from the beginning.
>>
>> However I am not sure if we can actually sleep in the USB reset
>> handler and what we need to do to restore the correct altsetting
>> in there. This could potentially fail, so please test ;)
>>
>> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
>> ---
>> drivers/bluetooth/btusb.c | 34 ++++++++++++++--------------------
>> 1 file changed, 14 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
>> index f3dfc0a..32cae73 100644
>> --- a/drivers/bluetooth/btusb.c
>> +++ b/drivers/bluetooth/btusb.c
>> @@ -245,7 +245,6 @@ struct btusb_data {
>>
>> unsigned long flags;
>>
>> - struct work_struct work;
>> struct work_struct waker;
>>
>> struct usb_anchor tx_anchor;
>> @@ -685,7 +684,6 @@ static int btusb_close(struct hci_dev *hdev)
>> if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags))
>> return 0;
>>
>> - cancel_work_sync(&data->work);
>> cancel_work_sync(&data->waker);
>>
>> clear_bit(BTUSB_ISOC_RUNNING, &data->flags);
>> @@ -827,18 +825,6 @@ done:
>> return err;
>> }
>>
>> -static void btusb_notify(struct hci_dev *hdev, unsigned int evt)
>> -{
>> - struct btusb_data *data = hci_get_drvdata(hdev);
>> -
>> - BT_DBG("%s evt %d", hdev->name, evt);
>> -
>> - if (hdev->conn_hash.sco_num != data->sco_num) {
>> - data->sco_num = hdev->conn_hash.sco_num;
>> - schedule_work(&data->work);
>> - }
>> -}
>> -
>> static inline int __set_isoc_interface(struct hci_dev *hdev, int altsetting)
>> {
>> struct btusb_data *data = hci_get_drvdata(hdev);
>> @@ -882,9 +868,8 @@ static inline int __set_isoc_interface(struct hci_dev *hdev, int altsetting)
>> return 0;
>> }
>>
>> -static void btusb_work(struct work_struct *work)
>> +static void btusb_update_isoc_altsetting(struct btusb_data *data)
>> {
>> - struct btusb_data *data = container_of(work, struct btusb_data, work);
>> struct hci_dev *hdev = data->hdev;
>> int new_alts;
>> int err;
>> @@ -932,6 +917,18 @@ static void btusb_work(struct work_struct *work)
>> }
>> }
>>
>> +static void btusb_notify(struct hci_dev *hdev, unsigned int evt)
>> +{
>> + struct btusb_data *data = hci_get_drvdata(hdev);
>> +
>> + BT_DBG("%s evt %d", hdev->name, evt);
>> +
>> + if (hdev->conn_hash.sco_num != data->sco_num) {
>> + data->sco_num = hdev->conn_hash.sco_num;
>> + btusb_update_isoc_altsetting(data);
>> + }
>> +}
>> +
>> static void btusb_waker(struct work_struct *work)
>> {
>> struct btusb_data *data = container_of(work, struct btusb_data, waker);
>> @@ -1404,7 +1401,6 @@ static int btusb_probe(struct usb_interface *intf,
>>
>> spin_lock_init(&data->lock);
>>
>> - INIT_WORK(&data->work, btusb_work);
>> INIT_WORK(&data->waker, btusb_waker);
>> spin_lock_init(&data->txlock);
>>
>> @@ -1540,8 +1536,6 @@ static int btusb_suspend(struct usb_interface *intf, pm_message_t message)
>> return -EBUSY;
>> }
>>
>> - cancel_work_sync(&data->work);
>> -
>> btusb_stop_traffic(data);
>> usb_kill_anchored_urbs(&data->tx_anchor);
>>
>> @@ -1606,8 +1600,8 @@ static int btusb_resume(struct usb_interface *intf)
>> play_deferred(data);
>> clear_bit(BTUSB_SUSPENDING, &data->flags);
>> spin_unlock_irq(&data->txlock);
>> - schedule_work(&data->work);
>>
>> + btusb_update_isoc_altsetting(data);
>> return 0;
>>
>> failed:
>>
>
> I have been testing this patch for the last two days at the UPF in Vienna. It was running fine most of the time, but I experienced two crashes. Both crashes appeared when there was an active call and the phone transferred audio to the phone and back. Both times I wasn't able to reproduce, when I restarted everything and tested again it worked fine.
>
> Unfortunately the kernel log is not complete but, when it failed the kernel reported:
> [147.344546] Bluetooth: hci0 SCO packet for unknown connection handle 5
> [147.354515] Bluetooth: hci0 SCO packet for unknown connection handle 21
> [147.354537] Bluetooth: hci0 SCO packet for unknown connection handle 29
> [147.354548] Bluetooth: hci0 SCO packet for unknown connection handle 65534
> [147.364574] Bluetooth: hci0 SCO packet for unknown connection handle 65532
> [147.364581] Bluetooth: hci0 SCO packet for unknown connection handle 27
> …
what kind of hardware where you testing with?
This handle mismatch normally means that our SCO packet frames are out of sync. I think we are not doing a good job trying to keep them nicely lined up.
For the crash, do you happen to have a backtrace of the crash. Personally I was worried about the reset handling and not the actual alternate setting switching.
Regards
Marcel
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