Bug#703468: [3.2.35-2 -> 3.2.39-1 regression] fails to boot on apple iMac

[Geoff Crompton <geoffc@trinity.unimelb.edu.au>]

On 11/04/13 10:54, Geoff Crompton wrote:
> I've also built a 3.2.39 kernel with some patches stripped. This kernel
> still does exhibit the problem, suggesting the patches I stripped out
> are not responsible. Those patches are:
>
> bugfix/x86/drm-i915-kick-any-firmware-framebuffers-before-claim.patch
> bugfix/x86/drm-i915-Only-kick-out-vesafb-if-we-takeover-the-fbc.patch
> bugfix/x86/drm-i915-add-quirk_invert_brightness-for-ncr-machine.patch
> bugfix/x86/drm-i915-Close-race-between-processing-unpin-task-an.patch
> bugfix/all/i915-ensure-that-VGA-plane-is-disabled.patch
> bugfix/x86/drm-i915-Only-increment-the-user-pin-count-after-suc.patch
> bugfix/x86/drm-i915-Disable-AsyncFlip-performance-optimisations.patch
> bugfix/x86/drm-i915-GFX_MODE-Flush-TLB-Invalidate-Mode-must-be-.patch
> bugfix/x86/drm-i915-dump-UTS_RELEASE-into-the-error_state.patch
>
> Here is a quick summary of what kernel's I've tried so far:
> works 3.8.5
> works 3.6.9
> fails 3.4.4
> fails 3.2.41-2
> fails 3.2.39-2
> works 3.2.35-2
>
> Looking at snapshots.debian.org, I'll try 3.5.5-1, as it seems so far
> Jonathan has been trying to get me to bisect in on the bug.


I've done some more testing, using kernels from snapshot.debian.org. I 
downloaded all the available versions between what we'd already tested. 
I've tried to bisect onto the range. I now know:

works 3.8.5
works 3.6.9
works 3.6.6
works 3.6.4
fails 3.5.5-1
fails 3.4.4
fails 3.2.41-2
fails 3.2.39-2
works 3.2.35-2

This suggests the bug is introduced from 3.5.5 upto 3.6.3, and has been 
backported into a Debian kernel above 3.2.35-2.

Hope that is helpful, what is the next step?

Cheers,
Geoff