Re: 2.6.39-rc2 regression: X201s fails to resumeb77dcf8460ae57d4eb9fd3633eb4f97b8fb20716

From: Marcel Holtmann
Date: Mon Apr 11 2011 - 17:40:42 EST


Hi Thomas,

> > > > Can the bluetooth folks please have a look at that ASAP? The obvious
> > > > fast fix for Linus tree is to revert the second hunk for now, but this
> > > > needs to be fixed proper.
> > >
> > > Who will submit this patch? I'd rather have your name on it so that
> > > people come complain at you...
> >
> > I took a shot at it and just sent a patch (also attached for convenience)
> > that should solve the problem.
>
> Aaarg. No. That patch reverts both hunks.
>
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -586,9 +586,6 @@ static int hci_dev_do_close(struct hci_dev *hdev)
> hci_req_cancel(hdev, ENODEV);
> hci_req_lock(hdev);
>
> - /* Stop timer, it might be running */
> - del_timer_sync(&hdev->cmd_timer);
> -
> if (!test_and_clear_bit(HCI_UP, &hdev->flags)) {
> hci_req_unlock(hdev);
> return 0;
>
> As I said before you need that first hunk to stay for the case where
> there is no device up and you return via the !HCI_UP check. You just
> moved back to the state before as the stupid timer is active for
> whatever reason even when HCI_UP is not set.

if I read this right then we have the case that we arm this timer for no
real reason. A device in !HCI_UP should have nothing running. Certainly
not the cmd_timer since it will never process any commands.

According to Gustavo, the problem is really in the hci_reset logic were
we arm the timer even when shutting down the device.

Regards

Marcel


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