Bug#805880: linux-image 3.2.73-1 causes video to hang at boot

[Thomas Guyot-Sionnest <dermoth@aei.ca>]

Package: linux-image-3.2.0-4-amd64
Version: 3.2.73-1
Severity: critical

Hi,

This morning I updated my Dell D630 laptop running Debian Wheezy; upon
reboot the video got stuck on a black screen with only the mouse
visible, but not moving. Upon quick investigation it appears to be a
kworker thread getting stuck:

Nov 23 09:12:25 kernel: [    8.919834] Process kworker/u:1 (pid: 168,
threadinfo ffff880119314000, task ffff8801192d3840)
Nov 23 09:12:25 kernel: [    8.919995]  ffffffffa02d4685
0000000000000046 ffff880119f38000 ffff880119540000
Nov 23 09:12:25 kernel: [    8.920115]  ffff880119f39770
0000000000000001 ffff880119d37c05 ffff880119540020
Nov 23 09:12:25 kernel: [    8.920115]  ffffffffa02d618b
ffff880119f39780 ffff880119540000 0000000000000000
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffffa02d4685>] ?
i915_gem_retire_requests_ring+0x15/0x172 [i915]
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffffa02d618b>] ?
i915_gem_retire_requests+0x68/0x78 [i915]
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffffa02d61f3>] ?
i915_gem_retire_work_handler+0x58/0x122 [i915]
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffff8105b7eb>] ?
process_one_work+0x161/0x269
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffff8105c7b4>] ?
worker_thread+0xc2/0x145
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffff8105c6f2>] ?
manage_workers.isra.25+0x15b/0x15b
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffff8105f901>] ?
kthread+0x76/0x7e
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffff81358d34>] ?
kernel_thread_helper+0x4/0x10
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffff8105f88b>] ?
kthread_worker_fn+0x139/0x139
Nov 23 09:12:25 kernel: [    8.920115]  [<ffffffff81358d30>] ?
gs_change+0x13/0x13
Nov 23 09:12:25 kernel: [    8.920115]  RSP <ffff880119315dc8>

This issue appears to have been reported to the LKML already:
https://lkml.org/lkml/2015/10/1/861

The kernel was updated from 3.2.68-1+deb7u3 to 3.2.73-1. According to
the package's changelog
(http://metadata.ftp-master.debian.org/changelogs//main/l/linux/linux_3.2.73-1_changelog)
the issue may have been introduced in version 3.2.71-1:

  [ Ben Hutchings ]
  * drm, agp: Update to 3.4.109:
[...]
    - drm/radeon: Use drm_calloc_ab for CS relocs

This is the exact commit pointed out as the culprit in the reply to the
LKML post I pointed out.

As expected, downgrading the package back to 3.2.68-1+deb7u3 resolved
the issue

NB: I set the severity as critical considering it renders the system
unusable (you have to ssh in if enabled; possibly booting up in text
mode might work too) and the update replaces the old, working, kernel so
that you can't just pick an older version in Grub.

Regards,

-- 
Thomas