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From: Oliver Neukum <oneukum@suse.de>
Organization: Novell
To: Mark Lord <lkml@rtr.ca>
Subject: Re: [PATCH] usb-serial regression fix
Date: Tue, 13 Mar 2007 14:50:23 +0100
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Cc: Jim Radford <radford@blackbean.org>, Greg KH <greg@kroah.com>,
       linux-usb-devel@lists.sourceforge.net, Adrian Bunk <bunk@stusta.de>,
       Andrew Morton <akpm@linux-foundation.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Am Dienstag, 13. März 2007 14:39 schrieb Mark Lord:
> Oliver Neukum wrote:
> >
> > If we get to destroy_serial(), how can ports still be open?
> 
> (1) open up a ckermit session on /dev/usb_serial_port_0.
> (2) suspend the machine (to RAM).
> (3) the suspend logic "removes" all USB devices.

No,

any open port has taken a reference in serial_open():
	serial = usb_serial_get_by_index(tty->index);

destroy_serial() can be called only when the refcount goes to zero. How
can there be open ports?

	Regards
		Oliver