nouveau graphical corruption in 3.13.2

[Daniel J Blueman]

On 9 February 2014 02:57, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Sat, Feb 8, 2014 at 10:38 AM, Daniel J Blueman <daniel at quora.org> wrote:
>> Interestingly, there was graphical failure booting 3.6.11, even
>> nvidia-current fails to initialise, but these two issues could be due
>> to running the Xorg stack in Ubuntu 14.04 pre-release. Using
>> nouveau.noaccel=1 works great for the first X session, but after
>> logging out, lightdm and the next session experiences this consistent
>> screen corruption:
>>
>> http://quora.org/nouveau-corruption.jpg
>
> Does that just happen in 3.6.11 or even in 3.13? If the latter, that.
> points to some key lack of understanding of... something. With
> noaccel, we're not using pgraph or anything fancy -- it's just a
> framebuffer, basically. So if we can't even render _that_ right...
>
> Hopefully someone else will pipe up re your other issues -- my
> knowledge base on this is exhausted :(

Interestingly, it turns out that the screen corruption occurs on every
boot (booting with nouveau.noaccel=1 for now), and I can consistently
work around it by one suspend-resume cycle.

To that effect, I've captured kernel message output booting 3.14-rc3
with 'nouveau.noaccel=1 nouveau.debug=trace,DEVINIT=spam drm.debug=0x6
log_buf_len=16M', and performed a suspend-resume cycle:
http://quora.org/nouveau-log.txt

Ben et al, would some specific register tracing or otherwise help to
locate the issue?
-- 
Daniel J Blueman