Re: [PATCH] intel-agp.c: Fix crash when accessing nonexistent GTT entries in i915

[Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>]

On Sun, Mar 21, 2010 at 2:58 PM, Zhenyu Wang <zhenyuw@linux.intel.com> wrote:
> On 2010.03.20 14:04:56 +0100, Miguel Ojeda wrote:
>> On Fri, Mar 19, 2010 at 9:27 PM, Andrew Morton
>> <akpm@linux-foundation.org> wrote:
>> > On Thu, 11 Mar 2010 16:54:26 +0100
>> > Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote:
>> >
>> >> Attached dmesg, lspci -vv, config and xorg.
>> >>
>> >> When the X server crashes, the kernel does not report anything
>> >
>> > This seems to have gone all quiet?
>>
>> It seems so, I was about to ping Zhenyu.
>
> Could you try recent X.org intel driver release? Your failure X log
> showed some pretty old UMS driver's render flush time out message,
> I think whose version never has been well tested with new kms/gem stuff.
>

Sure. Debian Stable got version 2.3.

>>
>> >
>> > As this was a 2.6.32->2.6.32.4 regression, I assume that it's also a
>> > 2.6.32->2.6.33 regression?
>>
>> Yep. All kernels I tested since 2.6.32.4 crash, including 2.6.32.10,
>> 2.6.33 and 2.6.34-rc1. See my original message for more details about
>> the crash.
>>
>
> Could you bisect? I doubt it's caused by David's patch, as if it is, you
> will have trouble at early agp init time, instead of current problem looks
> like something causing rendering hang..and I can't think of how mapping GTT
> to a scratch page could cause problem in case GTT bar is truely 256K.

I bisected in order to find the commit 5877960869333e42ebeb733e8d9d5630ff96d350.

I don't know if such commit is really the true problem (does not seem
so if you are right); however, it is the commit that breaks the X
server as I stated in the original message.

>
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> Open Source Technology Center, Intel ltd.
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