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Message-ID: <476ACDC6.8070904@linux.intel.com>
Date: Thu, 20 Dec 2007 21:17:10 +0100
From: Arjan van de Ven <arjan@linux.intel.com>
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To: David Newall <david@davidnewall.com>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>, Marcel Holtmann <marcel@holtmann.org>,
       linux-kernel@vger.kernel.org
Subject: Re: Kernel bug: bluetooth meets TTY layer
References: <476A895C.7040903@linux.intel.com> <476AC51F.70400@davidnewall.com>
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David Newall wrote:
> Hi Arjan,
> 
> I've not been able to find this file, "drivers/bluetooth/hci_tty.c", but 
> anyway, This seems to be what happens: Hci_uart_close() flushes using 
> hci_uart_flush().  Subsequently, in hci_dev_do_close(), (one step in 
> hci_unregister_dev()), hci_uart_flush() is called again.  The comment in 
> uart_flush_buffer(), relating to the WARN_ON(), indicates you can't 
> flush after the port is closed; which sounds reasonable.  I think 
> hci_uart_close() should set hdev->flush to NULL before returning.  
> Hci_dev_do_close() does check for this.  The code path is rather 
> involved and I'm not entirely clear of all steps, but I think that's 
> what should be done.
> 
> Patch for stupidly obsolete kernel attached.

looks reasonable; unfortunately I don't know the tty code well enough to judge this patch...
Alan?