Re: [PATCH] intel-agp.c: Fix crash when accessing nonexistent GTT entries in i915

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 27 Apr 2010 22:06:21 +0200
Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote:

> On Tue, Apr 27, 2010 at 7:57 PM, Andrew Morton
> <akpm@linux-foundation.org> wrote:
> > On Thu, 25 Mar 2010 17:55:56 +0100
> > Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote:
> >
> >> On Wed, Mar 24, 2010 at 7:14 PM, Andrew Morton
> >> <akpm@linux-foundation.org> wrote:
> >> > On Tue, 23 Mar 2010 12:40:05 +0100
> >> > Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote:
> >> >
> >> >> On Tue, Mar 23, 2010 at 5:14 AM, Christian Kujau <lists@nerdbynature.de> wrote:
> >> >> > On Mon, 22 Mar 2010 at 20:57, Andrew Morton wrote:
> >> >> >> On Sun, 21 Mar 2010 16:30:20 +0100 Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote:
> >> >> >> > I bisected in order to find the commit 5877960869333e42ebeb733e8d9d5630ff96d350.
> >> >> >
> >> >> > I believe this[0] is fc61901373987ad61851ed001fe971f3ee8d96a3 upstream:
> >> >>
> >> >> Indeed. Also in
> >> >>
> >> >> http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.32.y.git;a=commit;h=fc61901373987ad61851ed001fe971f3ee8d96a3
> >> >
> >> > Does reverting that patch from the current code fix the crash?
> >>
> >> Yes. In addition, applying the patch I provided also fixes it in current code.
> >>
> >
> > Well great. __A whole pile of new stuff has turned up in linux-next's
> > drivers/char/agp/intel-agp.c. __As far as I can tell none of it
> > address the regression which you've reported and your patch no longer
> > applies at all so I have to drop the patch.
> >
> > Perhaps "agp/intel: put back check that we have a driver for the
> > bridge" fixes it, but it isn't tagged for -stable backporting.
> 
> I can try linux-next and see if it works again.

Thanks.

> In addition, I have to test the regression with some newer X version
> yet, as Zhenyu told me.

That would seem to be counter-productive.  If you install a newer X and
the bug goes away, you've just gone and made it harder for yourself to
reproduce the bug.