[Nouveau] GeForce 6100 (NV4E) & nouveau regression in 3.12

[Ilia Mirkin]

On Sun, Feb 16, 2014 at 2:15 PM, Rafał Miłecki <zajec5 at gmail.com> wrote:
> 2014-02-16 19:55 GMT+01:00 Ilia Mirkin <imirkin at alum.mit.edu>:
>> On Sun, Feb 16, 2014 at 10:17 AM, Rafał Miłecki <zajec5 at gmail.com> wrote:
>>> 2014-02-11 11:41 GMT+01:00 Ilia Mirkin <imirkin at alum.mit.edu>:
>>>> (b) bisect. you can (almost) definitely restrict the bisect to
>>>> drivers/gpu/drm/nouveau. if you have additional computational power, i
>>>> would recommend looking into distcc for speeding up the compiles. it
>>>> may be interesting to also try 3.6.x since 3.7 received a pretty big
>>>> rewrite. but a git bisect is a lot more direct in figuring these
>>>> things out :)
>>>>
>>>> After I watched your video, it definitely brought back memories of
>>>> another bug or perhaps email on this list a while back (definitely
>>>> within the past year), but unfortunately I can't quite place it :(
>>>
>>> I've finally bisected between 3.10 and 3.11:
>>>
>>> 78ae0ad403daf11cf63da86923d2b5dbeda3af8f is the first bad commit
>>> commit 78ae0ad403daf11cf63da86923d2b5dbeda3af8f
>>> Author: Ben Skeggs <bskeggs at redhat.com>
>>> Date: Wed Aug 21 11:30:36 2013 +1000
>>>
>>>     drm/nv04/disp: fix framebuffer pin refcounting
>>>
>>> I've booted that commit and one commit older few times. Every time I
>>> booted 78ae0ad I got corruption. Every time I booted 6ff8c76 (it's the
>>> earlier commit), it was OK.
>>
>> But I bet if you restart X, you get a backtrace, right?
>
> That's right.
>
> 78ae0ad:
> Corruptions
>
> 6ff8c76:
> WARNING: at drivers/gpu/drm/nouveau/nouveau_bo.c:151
> nouveau_bo_del_ttm+0x80/0x90 [nouveau]()
> (after quiting X by "init 3")

OK, as expected. And those backtraces are the fallout from a boatload
of ttm changes that went into 3.10. So 3.9 should be safe for you :)

So that these findings don't get lost/forgotten, mind filing a bug
with your various findings as per
http://nouveau.freedesktop.org/wiki/Bugs/ ? Unfortunately I have never
observed your particular issue on any of my pre-nv50 cards
(nv05/18/34/42/44), so there must be some special component. Perhaps
it's the IGP-ness. Although others with IGP's haven't complained about
this.

  -ilia