Re: [stable] [PATCH] uio/gen-pci: don't enable interrupts in ISR

[Greg KH <greg@kroah.com>]

On Wed, Aug 10, 2011 at 11:40:12AM +0300, Michael S. Tsirkin wrote:
> On Tue, Aug 09, 2011 at 08:53:41PM +0200, Hans J. Koch wrote:
> > On Tue, Aug 09, 2011 at 02:37:43PM +0300, Michael S. Tsirkin wrote:
> > > > 
> > > > Should I hack up a patch to remove the lock, or do you have anything in your
> > > > pipeline?
> > > 
> > > 
> > > Please do.
> > > 
> > 
> > Here it is:
> > 
> > Greg (and anyone else...), you can also pull this from branch "uio-for-greg" from
> > 
> > git://hansjkoch.de/git/linux-hjk
> > 
> > 
> > >From ff74627ade002d40fe1f902b7aadab8b1f15f889 Mon Sep 17 00:00:00 2001
> > From: "Hans J. Koch" <hjk@hansjkoch.de>
> > Date: Tue, 9 Aug 2011 20:34:31 +0200
> > Subject: [PATCH] uio: uio_pci_generic: Remove useless spin_lock
> > 
> > The spin_lock in uio_pci_generic.c is only used in the interrupt
> > handler, which cannot be executed twice at the same time.
> > That makes the lock rather pointless. This patch removes it.
> > 
> > Cc: "Michael S. Tsirkin" <mst@redhat.com>
> > Cc: Chris Wright <chrisw@redhat.com>
> > Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
> > Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> > Cc: Anthony Foiani <anthony.foiani@gmail.com>
> > Reported-by: Anthony Foiani <anthony.foiani@gmail.com>
> > Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> > Signed-off-by: Hans J. Koch <hjk@hansjkoch.de>
> 
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> I also suggest this for the stable trees.

Why, it's not fixing a bug that anyone hits, right?

greg k-h