[Intel-gfx] [G35 KMS] regression confuses monitor to think resolution is 1920x1198

[Martin Bergström]

Hi!

Thought I'd send this to the mailing list before submitting to the
freedesktop.org bugzilla.

Diagnostics files can be found at http://kylie.dyndns.org/~martin/blurry/

Any thoughts? Workarounds? Should I buy some other hardware instead?
Should I submit a bug report already?

Cheers,
Martin



Product=DRI. Component=DRM/Intel.

Summary: [G35 KMS] regression confuses monitor to think resolution is
1920x1198

-- chipset: G35
-- system architecture: i686
-- kernel version: 2.6.32-5-686 vs 2.6.39-2-686-pae
-- Linux distribution: Debian GNU/Linux Wheezy ("testing")
-- Mobo model: ASUS P5E-V HDMI using onboard graphics
-- Display connector: HDMI-converted-to-DVI

Reproduce steps: Boot up. Wait for kernel mode setting to do its stuff.
Always occurs.

-- intel_reg_dumper output
A tool by that name is not created when I build
http://xorg.freedesktop.org/archive/individual/app/intel-gpu-tools-1.0.tar.bz2,
maybe the bug submitting guidelines needs to be updated?
Output from intel_gpu_dump (from Debian package intel-gpu-tools_1.0.2-1)
are available.


Problem description:

I'm running Debian testing ("wheezy") and few weeks^H^H^H^H^Hmonths ago
the Linux kernel was updated from 2.6.32 to 2.6.38 (and then 2.6.39).
With this a regression occured causing some blurryness in two horizontal
bands on my brand new EIZO FLEXSCAN S2433WFS monitor. Under 2.6.39 the
monitor OSD info says the resolution is 1920x1198, not 1920x1200 as it
does with 2.6.32. The computer says the resolution is 1920x1200 under
all kernel versions.

I'm using the Intel graphics (driver i915) on the motherboard (ASUS
P5E-V HDMI), and on its HDMI output there's a thingamajig converting
HDMI to DVI (supplied with the motherboard), and from there a DVI-cable
to the monitor. (Pretty sure it's DVI-D.) The motherboard also has an
unused VGA-port.

The blurriness is noticeable even before X starts, as soon as the
kernel's KMS kicks in. If I disable KMS (modeset=0 in
/etc/modprobe.d/i915-kms.conf) X doesn't start, which is not surprising
considering that all over the internet it says KMS is required for X
with Intel graphics.

X configures itself automatically, there's no config file. (Probably not
relevant considering the blurriness is noticeable before X starts.)

I have done various diagnostics and nothing obvious stands out that I
can see. The only things of note are:

1. xrandr calls the output "DVI1" under 2.6.32 and "HDMI1" under 2.6.39.

2. xrandr says "HDMI1 clones VGA1" under 2.6.38, nothing like that under
2.6.32.

3. xrandr mentions "force_audio: 0" under 2.6.38, not under 2.6.32.
Trying to alter this makes not difference.

4. "fbset --show" says "accel true" under 2.6.38 but not under 2.6.32.
Turning accel off make no difference.