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Date: Sat, 24 May 2014 16:42:42 +0200
From: Johan Hovold <jhovold@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org, Peter Hurley <peter@hurleysoftware.com>,
        One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
        Xiao Jin <jin.xiao@intel.com>, david.a.cohen@linux.intel.com,
        yanmin.zhang@intel.com, Johan Hovold <jhovold@gmail.com>,
        Oliver Neukum <oneukum@suse.de>
Subject: Re: [PATCH] USB: cdc-acm: fix broken runtime suspend
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On Mon, Apr 14, 2014 at 09:58:12PM +0200, Johan Hovold wrote:
> The current ACM runtime-suspend implementation is broken in several
> ways:
> 
> Firstly, it buffers only the first write request being made while
> suspended -- any further writes are silently dropped.
> 
> Secondly, writes being dropped also leak write urbs, which are never
> reclaimed (until the device is unbound).
> 
> Thirdly, even the single buffered write is not cleared at shutdown
> (which may happen before the device is resumed), something which can
> lead to another urb leak as well as a PM usage-counter leak.
> 
> Fix this by implementing a delayed-write queue using urb anchors and
> making sure to discard the queue properly at shutdown.
> 
> Reported-by: Xiao Jin <jin.xiao@intel.com>
> Signed-off-by: Johan Hovold <jhovold@gmail.com>

Greg, 

I understand yoǘ're on your way home from Japan and are getting ready to
work through the 3.16 patch queue.

Could you please discard this one for now? I've found a couple of more
PM related problems and I'll submit a slight update of this one as part
of a larger series of fixes instead.

Thanks,
Johan