From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marcin Slusarz <marcin.slusarz@gmail.com>
Subject: Re: drm/nouveau: crash regression in 3.5
Date: Thu, 2 Aug 2012 18:56:30 +0200
Message-ID: <20120802165630.GA3058@joi.lan>
References: <500ED9EC.5040309@odi.ch>
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 <50113E76.9090706@odi.ch>
 <20120729201532.GA3566@joi.lan>
 <50166D15.7090305@odi.ch>
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To: Ortwin =?utf-8?B?R2zDvGNr?= <odi@odi.ch>
Cc: linux-kernel@vger.kernel.org, bskeggs@redhat.com, dri-devel@lists.freedesktop.org, airlied@redhat.com
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On Thu, Aug 02, 2012 at 01:26:55PM +0200, Ortwin Gl=C3=BCck wrote:
> I have managed to turn the crash into a WARN_ON, by adding this to th=
e=20
> begin of nouveau_software_vblank():
>=20
>          if (!psw) {
>                  WARN_ON(1);
>                  return;
>          }

Yes, I know about it, but this change fixes only a symptom. We should n=
ot get
into this code at all without enabling vblank.

> And I have also managed to load the module manually instead by udev. =
So=20
> I am happy to attach a full log of what's going on here. See also my=20
> added printk's starting with XXX that mark some interesting points in=
=20
> the initialization.
>=20
> This should give you enough information to track down the cause of th=
e=20
> problem. To my non-expert eyes it looks like "noaccel" prevents=20
> registration of NVOBJ_ENGINE_SW or at least delays it too much.

Yes, that's what I wrote in my last patch - with noaccel it's not regis=
tered,
which leads to NULL pointer derefence.

I'm currently out of ideas why my patch does not work. But I have some =
ideas
how to debug it. Can you come to nouveau IRC channel at freenode and do=
 some
additional tests? My nick is "joi" and I'm available on IRC between 6pm=
 and
11pm CEST.

Marcin