Bug#580601: Related to KMS in 2.6.32

[Fernando Lemos <fernandotcl@gmail.com>]

On Sat, May 22, 2010 at 4:21 PM, Julien Cristau <jcristau@debian.org> wrote:
> On Sat, May 22, 2010 at 21:09:16 +0200, Brice Goglin wrote:
>
>> On 22/05/2010 20:42, Fernando Lemos wrote:
>> > This problem seems to be related to KMS in 2.6.32:
>> >
>> > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/549989
>> >
>> > (several similar reports can be found on other distro's bugtrackers)
>> >
>> > Either disabling KMS entirely (i915.modeset = 0 in /etc/defaults/grub)
>> > or disabling the powersave option (i915.powersave = 0) solves the
>> > problem. It looks like a kernel bug in 2.6.32.
>> >
>>
>> powersave is already disabled by default (see /etc/modprobe.d/i915-kms.conf)
>>
> err.  no it's not.

It really is not enabled by default:

fernando@vostro:~$ cat /etc/modprobe.d/i915-kms.conf
options i915 modeset=1

>
> Fernando, do you still have this issue with 2.6.34 (from experimental)?
> If it's fixed upstream it might be possible to backport the fix to
> squeeze's kernel.

I just installed 2.6.34 from experimental (added experimental to
sources.list and apt-get installed -t experimental
linux-image-2.6.34-1-amd64) and reverted my changes to
/etc/defaults/grub and re-ran update-grub to make sure. So I'm using
modeset=1 (it's in 915-kms.conf) and powersave is unchanged, it should
be enabled by default:

fernando@vostro:~$ uname -a
Linux vostro 2.6.34-1-amd64 #1 SMP Wed May 19 19:06:22 UTC 2010 x86_64 GNU/Linux
fernando@vostro:~$ dpkg -l | grep linux-image
ii  linux-image-2.6-amd64                 2.6.32+27
  Linux 2.6 for 64-bit PCs (meta-package)
ii  linux-image-2.6.32-5-amd64            2.6.32-13
  Linux 2.6.32 for 64-bit PCs
ii  linux-image-2.6.34-1-amd64            2.6.34-1~experimental.1
  Linux 2.6.34 for 64-bit PCs
fernando@vostro:~$

The screen flickered 4 times during the time I was composing this
e-mail, so I guess it's not fixed upstream yet.

If there's anything else I can test, please let me know.

Thanks,