Re: [AGPGART] intel_agp: use table for device probe

[Carlo Wood <carlo@alinoe.com>]

On Sun, Jun 17, 2007 at 03:07:14PM -0400, Dave Jones wrote:
> Sometimes things fall through the cracks..
> I haven't heard any similar problems, which makes it somewhat odd.

Ok. Well, the lockup is all to real here :p

I suspect a memory corruption going on, as under certain circumstances
there is printed more after the "agpgart: Detected an Intel 965G
Chipset." -- that is, the kernel *sometimes* doesn't hang silently,
but either reboots by itself (hard reset) or prints something
that looks like a total crash to me. Often, this is prefixed by
the name of running process. I am sorry, I never wrote any of that
down. Only the last time, it then went like:

agpgart: Detected an Intel 965G Chipset.
modprobe: Corrupt page table at address 20
PGD 178c6c067 PUD 201000c0049c04f BAD

This very same kernel (I boot it several times to see how
reproducable things were) always prints "agpgart: Detected an Intel 965G
Chipset." but then either hangs (two times), prints the above
and hangs (one time) or hard resets (one time).

Then I also booted the other kernels several times, and kernels
that booted fine ALWAYS boot fine - while kernels that locked
up (that I tested by booting them three times) only printed
the agpgart line and locked up three times.

>  > The patch causes my machine to lock up and/or crash
>  > in various ways (depending on the exact version of the kernel),
>  > very shortly after printing: agpgart: Detected an Intel 965G Chipset.
>  > 
>  > The first kernel version that stops doing that is 2.6.22-rc5.
>  > I used git bisect once more to find the patch that fixes this bug:
>  > I am mailing this mostly because the comment doesn't seem to indicate
>  > that the author is aware that this patch fixes an existing regression
>  > (it worked fine for me with 2.6.18).
> 
> Indeed, it was unknown to me too, this should have just been
> a clean-up.

I hope you saw my later post too? I sent it to you too - but also to the
list, so I don't know if you'll notice it.

The Subject of that post is: 2.6.22-rc5 regression

I concluded too soon that 2.6.22-rc5 was working :(.
I just really tested it and it doesn't! Same error.

Please have a look at that other post of me and lets continue this
thread there.

> Out of curiousity, I'd like to see your lspci
> (not -v or anything, just run with no args)

I'll add that to that other thread.

-- 
Carlo Wood <carlo@alinoe.com>