Hi Tomas,
> I have noticed a problem with a race condition fix introduced in
> 2.4.27-pre2 that causes the kernel to hang when disconnecting a
> Bluetooth USB dongle or doing 'hciconfig hci0 down'. No message is
> printed, the kernel just doesn't respond anymore.
>
> Seen in Changelog:
> Marcel Holtmann:
> o [Bluetooth] Fix race in RX complete routine of the USB drivers
>
> Reversing the following patch to hci_usb_rx_complete() makes 2.4.27-pre2
> up until 2.4.30 happy and does not hang when removing the dongle
> anymore. (bfusb.c has the same patch applied)
>
> 2.6.11.7 does not show the same problem, but has similar code to the
> "fixed" (that hangs) code in 2.4, so the real problem is probably
> somewhere else.
does the attached patch makes any difference?
Regards
Marcel
===== drivers/bluetooth/hci_usb.c 1.23 vs edited =====
--- 1.23/drivers/bluetooth/hci_usb.c 2004-07-31 13:02:43 +02:00
+++ edited/drivers/bluetooth/hci_usb.c 2005-04-09 15:37:12 +02:00
@@ -398,12 +398,12 @@
BT_DBG("%s", hdev->name);
+ /* Synchronize with completion handlers */
write_lock_irqsave(&husb->completion_lock, flags);
-
+ write_unlock_irqrestore(&husb->completion_lock, flags);
+
hci_usb_unlink_urbs(husb);
hci_usb_flush(hdev);
-
- write_unlock_irqrestore(&husb->completion_lock, flags);
MOD_DEC_USE_COUNT;
return 0;
