Am Dienstag 19 August 2008 16:31:18 schrieb Marcel Holtmann:
> Hi Oliver,
>
> > > > First you release the interface, then you unregister the hci.
> > >
> > > Putting it after hci_unregister_dev is an issue. The unregister will
> > > call __hci_dev_put and then in return will call the destruct callback
> > > which will free the data pointer.
> > >
> > > So either we use hci_dev_hold or make sure that disconnect can only
> > > disable the SCO interface. That comes directly with the first comment
> > > from you.
> >
> > Here is a new version. I am afraid normal hci_dev_hold would fail if
> > the disconnect happens because the btusb module is being unloaded.
>
> the btusb_stop_traffic change is bogus. You don't need that. The flush
> callback will be called to ensure that all TX traffic is released.
OK.
> I am not sure about hci_dev_hold. We ensure that a reference count to
> the module is hold when the HCI device is brought up.
But won't the module be marked as going away and make try_module_get()
fail?
Regards
Oliver
Signed-off-by: Oliver Neukum <oneukum@xxxxxxx>
---
--- linux-2.6.27-rc3/drivers/bluetooth/btusb.c.marcel 2008-08-19 10:21:51.000000000 +0200
+++ linux-2.6.27-rc3/drivers/bluetooth/btusb.c 2008-08-19 15:50:06.000000000 +0200
@@ -169,6 +169,7 @@ static struct usb_device_id blacklist_ta
struct btusb_data {
struct hci_dev *hdev;
struct usb_device *udev;
+ struct usb_interface *acl;
struct usb_interface *isoc;
spinlock_t lock;
@@ -822,6 +827,7 @@ static int btusb_probe(struct usb_interf
}
data->udev = interface_to_usbdev(intf);
+ data->acl = intf;
spin_lock_init(&data->lock);
@@ -890,7 +896,7 @@ static int btusb_probe(struct usb_interf
if (data->isoc) {
err = usb_driver_claim_interface(&btusb_driver,
- data->isoc, NULL);
+ data->isoc, data);
if (err < 0) {
hci_free_dev(hdev);
kfree(data);
@@ -922,13 +928,23 @@ static void btusb_disconnect(struct usb_
hdev = data->hdev;
- if (data->isoc)
- usb_driver_release_interface(&btusb_driver, data->isoc);
+ /* make sure we have a reference */
+ __hci_dev_hold(hdev);
- usb_set_intfdata(intf, NULL);
+ usb_set_intfdata(data->acl, NULL);
+ if (data->isoc)
+ usb_set_intfdata(data->isoc, NULL);
+ /* unregister before releasing any interface */
hci_unregister_dev(hdev);
+ if (intf == data->isoc)
+ usb_driver_release_interface(&btusb_driver, data->acl);
+ else if (data->isoc)
+ usb_driver_release_interface(&btusb_driver, data->isoc);
+
+ /* release the reference */
+ __hci_dev_put(hdev);
hci_free_dev(hdev);
}
--
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