Re: interference on display, Intel 945GM, 32bit system, kernel next

Krzysztof Kolasa
2015-07-21T12:48:28Z

On 21.07.2015 11:43, Chris Wilson wrote:
> On Tue, Jul 21, 2015 at 11:07:20AM +0200, Daniel Vetter wrote:
>> On Tue, Jul 21, 2015 at 10:58:50AM +0200, Krzysztof Kolasa wrote:
>>> On 21.07.2015 10:41, Daniel Vetter wrote:
>>>> I meant whether you can reset the bad commit and it's immediate parent
>>>> extensively to make sure the bisect is really correct. gpu's occasionally
>>>> take a while to hang themselves, so could be that the bisect was
>>>> mislead somewhere.
>>>
>>> Again I will bisect, more testing good sections.
>>>
>>> At the moment on my old laptop, the latest official, properly working kernel is 4.1.2
>> You don't need to redo the full bisect, only retest the bad and the parent
>> of the bad extensively. That's enough to confirm the bisect result for
>> sure.
> The bisection is misleading. It's a missing write-barrier.
> -Chris
>
tested again:

# good: [cd102a687beed1042824d5fa81c6ba8bfe78e6a4] drm/i915: Remove misleading comment around bind_to_vm
git bisect good cd102a687beed1042824d5fa81c6ba8bfe78e6a4
# bad: [0875546c5318c85c13d07014af5350e9000bc9e9] drm/i915: Fix up the vma aliasing ppgtt binding
git bisect bad 0875546c5318c85c13d07014af5350e9000bc9e9
# first bad commit: [0875546c5318c85c13d07014af5350e9000bc9e9] drm/i915: Fix up the vma aliasing ppgtt binding

Screen does not lie :) first bad is BAD, good is GOOD

on commit cd102a687beed10, computer worked steadily (with a large number of windows, applications) about an hour and stopped the tests, everything was OK

on commit 0875546c5318c85, after about one minute, the screen gone mad

Krzysztof