Ubuntu
linux package

Kernel mode switching causes frequent screen flickering with intel video card (not present with the same packages and kernel 2.6.30)

Bug #402982 reported by Vincenzo Ciancia
16
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Fix Released
High
Andy Whitcroft
Nominated for Karmic by Vincenzo Ciancia

Bug Description

If I boot with kernel 2.6.31 in karmic, I see the screen flickering a lot and can't use my system at all. I have an integrated intel video card using the xserver-xorg-video-intel driver. I attach the information that I gathered from the console by memory, if it's not enough ask me the rest and I'll reboot and get it.

If I disable kms by adding i915.modeset=0 to the kernel command line, the problem disappears.

See original description
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :
Vincenzo Ciancia (vincenzo-ml)
tags: added: regression-potential
Vincenzo Ciancia (vincenzo-ml)
summary: - Frequent screen flashing with intel video card (not present with the
- same packages and kernel 2.6.30)
+ Kernel mode switching causes frequent screen flashing with intel video
+ card (not present with the same packages and kernel 2.6.30)
description: updated
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote : Re: Kernel mode switching causes frequent screen flashing with intel video card (not present with the same packages and kernel 2.6.30)

The relevant output from lspci -nn is:

00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller [8086:27a2] (rev 03)

description: updated
summary: - Kernel mode switching causes frequent screen flashing with intel video
+ Kernel mode switching causes frequent screen flickering with intel video
card (not present with the same packages and kernel 2.6.30)
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :

Attaching a video that shows the problem.

Leann Ogasawara (leannogasawara)
Changed in linux (Ubuntu):
importance: Undecided → High
status: New → Triaged
Revision history for this message
Andy Whitcroft (apw) wrote :

@Vinvenzo -- I see you are reporting that against a v2.6.31-3 could you confirm that this error is still in the v2.6.31-4 kernels as there were a bunch of Intel updates there. Please report back here!

Changed in linux (Ubuntu):
assignee: nobody → Andy Whitcroft (apw)
status: Triaged → In Progress
status: In Progress → Incomplete
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :

Sure, I already tested and the same problem is with the latest kernels.

Changed in linux (Ubuntu):
status: Incomplete → In Progress
Revision history for this message
Andy Whitcroft (apw) wrote :

@Vincenzo -- thanks, could you then test the kernels in the PPA below which has the latest Intel updates applied, please report back here:

    https://edge.launchpad.net/~apw/+archive/red

Changed in linux (Ubuntu):
status: In Progress → Incomplete
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :

Andy: the 2.6.31 package in the PPA solves the flickering problem, thank you.

Changed in linux (Ubuntu):
status: Incomplete → In Progress
Revision history for this message
Andy Whitcroft (apw) wrote :

@Vincenzo -- thanks for testing that. A lot of these fixes went into the karmic final kernel could you test that and confirm whether the issue is fixed there. Please test 2.6.31-12.39 or later and report back here. Thanks!

Changed in linux (Ubuntu):
status: In Progress → Incomplete
Revision history for this message
Philip Muškovac (yofel) wrote :

Vincenzo: did you get to test the new kernel?

Leann Ogasawara (leannogasawara)
tags: added: regression-release
removed: regression-potential
Revision history for this message
Vincenzo Ciancia (vincenzo-ml) wrote :

I no longer have that laptop, and moreover, I decided to stop any further contribution to ubuntu because of Bug #405350 (not because of the bug itself, but because clearly ubuntu does not want to deal with it, and provide an explanation of reasons for the current situation).

Said this, I suppose that the regression was a temporary problem.

Vincenzo

Leann Ogasawara (leannogasawara)
tags: added: karmic
Revision history for this message
Andy Whitcroft (apw) wrote :

Belief is that this bug was caused by the power saving code which has been disabled in the older releases for most cards as it causes these sorts of flickering. Please file a new bug if this persists in Lucid or later.

Changed in linux (Ubuntu):
status: Incomplete → Fix Released
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