External monitor does not work with Intel 915

Bug #38729 reported by Tero Karvinen on 2006-04-08
Affects Status Importance Assigned to Milestone
xserver-xorg-video-intel (Ubuntu)

Bug Description

External monitor does not work on X on Intel 915.

I am using Intel 915 display adapter on Acer Travelmate 3004WTMi, external display connected to VGA port. Testing has been done with Dapper Flight.

External monitor (flatpanel) either displays "Cannot display this video mode" or (in the best case) clips of bottom and right part of screen. The clipping occurs both in X and in text mode.

Using CRT or video projector, picture is much more garbled.

External display does NOT work
- with 915resolution, without 915resolution
- when monitor is plugged in when computer is running, when monitor is connected when computer boots
- by pressing Fn-F5 (builtin, external, clone)

Filed this as it's own bug as requested by Paul in a similar bug #36550.

'lshw' shows internal monitor (display 0, 12,1" 1280x800 TFT) configured, but (probably) external monitor unclaimed (VGA connector, display 1).
  description: VGA compatible controller
  physical id: 2
  bus info: pci@00:02.0
display:1 UNCLAIMED
  physical id: 2.1
  bus info: pci@00:02.1

xorg.conf only seems to have definition for PCI:0:2:0:
  Section "Device"
 Identifier "Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller"
 Driver "i810"
 BusID "PCI:0:2:0"

My kernel parameters (from menu.lst) are
 /boot/vmlinuz-2.6.15-19-386 root=/dev/hda3 ro noapic nolapic pci=noacpi quiet splash
More about my config:

I have not yet been able to come up with any bypass for this bug.

lshw shows the second display, display:1 is unclaimed.

xorg.conf only mentions PCI:0:2:0 (not PCI:0:2:1).

The best success I've had: X image is shown on both screens, but clipped on bottom and right. Sadly, I have no detailed notes about the configuration that got me this far. The resolution in the image might be unacceptably low.

Xorg.0.log.old. This log is not necessarily taken at the same day when the external display tests were made, hope it still of use.

Despite of what I said in bug description, text mode does not work perfectly on external display. The picture is clipped on the right (and probably on the bottom too).

description: updated

The two screens have different proportions: external display is normal 4:3, integrated widescreen flatpanel is something like 16:9. If X thinks both of them have same proportions, it is not suprising that part of picture is clipped on another screen. Maybe the different proportions cause the distortion in the image too. Could this be fixed by some Xorg.conf configuration?

Here are some command outputs from Travelmate 3000:

Found a bypass for the bug. Now an external monitor works!

See attached xorg.conf and

It is still a bug though, an external monitor should work out of the box right after installation.

unggnu (unggnu) wrote :

Could you please recheck it with Gutsy RC or newer? It is shipped with the new Intel driver which should fix this issue. 915resolution is then not needed anymore.

unggnu (unggnu) on 2007-10-14
Changed in xserver-xorg-video-i810:
status: New → Incomplete
Timo Aaltonen (tjaalton) wrote :

No reply, closing the bug.

Changed in xserver-xorg-video-i810:
status: Incomplete → Invalid
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