[Intel-gfx] Major 2.6.38 / 2.6.39 regression ignored?

[Kirill Smelkov]

Hello Chris, everyone,

On Sat, May 21, 2011 at 04:40:17PM +0100, Chris Wilson wrote:
> On Sat, 21 May 2011 11:23:53 -0400, "Luke-Jr" <luke at dashjr.org> wrote:
> > On Saturday, May 21, 2011 4:41:45 AM Chris Wilson wrote:
> > > On Fri, 20 May 2011 11:08:56 -0700, Ray Lee <ray-lk at madrabbit.org> wrote:
> > > > [ Adding Chris Wilson (author of the problematic patch) and Rafael
> > > > Wysocki to the message ]
> > > > 
> > > > On Fri, May 20, 2011 at 10:06 AM, Luke-Jr <luke at dashjr.org> wrote:
> > > > > I submitted https://bugzilla.kernel.org/show_bug.cgi?id=33662 a month
> > > > > ago against 2.6.38. Now 2.6.39 was just released without the
> > > > > regression being addressed. This bug makes the system unusable... Some
> > > > > guys on IRC suggested I
> > > > > email, so here it is.
> > > > 
> > > > See the bugzilla entry for the bisection history.
> > > 
> > > Which has nothing to do with Luke's bug. Considering the thousand things
> > > that can go wrong during X starting, without a hint as to which it is nigh
> > > on impossible to debug except by trial and error. If you set up
> > > netconsole, does the kernel emit an OOPS with it's last dying breath?
> > 
> > Why assume it's a different bug? I would almost wonder if it might affect 
> > all Sandy Bridge GPUs. In any case, I no longer have the original 
> > motherboard (it was recalled, as I said in the first post), nor even the 
> > revision of it (it had other issues that weren't being fixed). I *assume* I 
> > will have the same problem with my new motherboard (Intel DQ67SW), but I 
> > haven't verified that yet. I'll be sure to try a netconsole when I have to 
> > reboot next and get a chance to try the most recent 2.6.38 and .39 kernels, 
> > but at the moment it seems reasonable to address the problem bisected in the 
> > bug, even if it turns out to be different.
> 
> The bisection is into an old DRI1 bug on 945GM. That DRI has inadequate
> locking between release and IRQ and so is prone to such races as befell
> Kirill should not surprise anyone. As neither UMS nor DRI supported SNB,
> I can quite confidently state they are separate bugs.
> -Chris

I see DRI1 is maybe buggy and old, but still, pre-kms X used to work ok
on kernels < 2.6.38, and starting from 2.6.38 the system is just
unusable because X either crashes the kernel (2.6.38), or does not start
at all (2.6.39):

https://bugzilla.kernel.org/show_bug.cgi?id=36052


It's a regression. It's blocking me to upgrade to newer kernels. I've
done my homework -- digged it and came with detailed OOPS on netconsole
and bisected to single commit. Could this please be fixed?


Thanks,
Kirill