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Date: Wed, 7 Dec 2011 17:54:35 +0200
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Amit Shah <amit.shah@redhat.com>
Cc: Virtualization List <virtualization@lists.linux-foundation.org>,
        Rusty Russell <rusty@rustcorp.com.au>, levinsasha928@gmail.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 04/12] virtio: console: Add freeze and restore
 handlers to support S4
Message-ID: <20111207155435.GB23845@redhat.com>
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On Wed, Dec 07, 2011 at 04:29:55PM +0530, Amit Shah wrote:
> On (Wed) 07 Dec 2011 [12:43:24], Michael S. Tsirkin wrote:
> 
> > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> > > index e14f5aa..fd2fd6f 100644
> > > --- a/drivers/char/virtio_console.c
> > > +++ b/drivers/char/virtio_console.c
> > > @@ -1844,6 +1844,60 @@ static unsigned int features[] = {
> > >  	VIRTIO_CONSOLE_F_MULTIPORT,
> > >  };
> > >  
> > > +#ifdef CONFIG_PM
> > > +static int virtcons_freeze(struct virtio_device *vdev)
> > > +{
> > > +	struct ports_device *portdev;
> > > +	struct port *port;
> > > +
> > > +	portdev = vdev->priv;
> > > +
> > > +	vdev->config->reset(vdev);
> > 
> > 
> > So here, cancel_work_sync might still be running.
> > If it does run, might it try to access the device
> > config?  Could not determine this quickly, if yes it's a problem.
> 
> Similar to the other comment: I don't see why just resetting device
> can cause config queue access to go bad.
> 
> 		Amit

Hmm, not sure anymore. Sorry.