[regression] resolution detection fails with multiple displays connected

[Andreas Schildbach]

Binary package hint: xserver-xorg-video-intel

On a Dell X1 (i915GMS) and an externally connected Dell 2405fpw:

Since upgraded to intrepid, when I have the external display connected, Ubuntu boots up with the wrong resolution for the internal display. Should be 1280 x 768, but is 1024 x 768 (according to xrandr). It's also not the correct resolution for the external display, which would be 1920 x 1200.

If I unconnect the external display and reload X, I get the correct resolution.

This problem has been confirmed for several combinations of displays (see comments). I wonder if there is any combination that works - maybe resolutions have to be exactly the same.

However, this is a regression from Hardy, which has the resolutions right on each of the tested combinations.

[unggnu (unggnu)]

I can confirm this behavior but please also attach your /etc/X11/xorg.conf and /var/log/Xorg.0.log. After login the resolution could be set through screen resolution which is restored every session.

[Andreas Schildbach (schildbach)]

With the latest update to xserver-xorg-video-intel 2.4.0, the bug is still present.

Note that setting the resolution after login is not a feasible workaround, because this does not have any effect on gdm.

[Andreas Schildbach (schildbach)]

This bug is still present on Intrepid Alpha 5.

I have also confirmed the problem with a second external monitor (Fujitsu Siemens MCM 19P1N).

[Andreas Schildbach (schildbach)]

Guest Sessions also get the wrong resolution(s) by default.

[Tormod Volden (tormodvolden)]

I have some similar output/monitor detection issues in bug #278032. Apparently, this will be improved in 2.5.

[Artur Brodowski (bzd)]

I have the same issue on Dell Latitude D830 and external Dell 1908FPt connected through a dock station.
With default X configuration (intel driver) the resolution is too high for the monitor to handle and it does not
fall back automatically to maximum 1280x1024. When using vesa driver, max resolution is detected fine.

I'm running daily updated Intrepid, starting with Beta release - and like Anreas, I did not have this problem
with Hardy.

$ xrandr
Screen 0: minimum 640 x 480, current 1280 x 1024, maximum 1280 x 1024
default connected 1280x1024+0+0 0mm x 0mm
   1280x1024 0.0*
   1024x768 0.0
   800x600 0.0
   640x480 0.0

$ sudo get-edid | parse-edid
parse-edid: parse-edid version 1.4.1
get-edid: get-edid version 1.4.1

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f00 bx=0x0 cx=0x0
 Function supported
 Call successful

 VBE version 300
 VBE string at 0x11110 "Intel(r)GM965/PM965/GL960 Graphics Chip Accelerated VGA BIOS"

VBE/DDC service about to be called
 Report DDC capabilities

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f15 bx=0x0 cx=0x0
 Function supported
 Call successful

 Monitor and video card combination does not support DDC1 transfers
 Monitor and video card combination supports DDC2 transfers
 0 seconds per 128 byte EDID block transfer
 Screen is not blanked during DDC transfer

Reading next EDID block

VBE/DDC service about to be called
 Read EDID

 Performing real mode VBE call
 Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
 Function supported
 Call successful

parse-edid: EDID checksum passed.

 # EDID version 1 revision 3
Section "Monitor"
 # Block type: 2:0 3:ff
 # Block type: 2:0 3:fc
 Identifier "DELL 1908FP"
 VendorName "DEL"
 ModelName "DELL 1908FP"
 # Block type: 2:0 3:ff
 # Block type: 2:0 3:fc
 # Block type: 2:0 3:fd
 HorizSync 30-81
 VertRefresh 56-76
 # Max dot clock (video bandwidth) 140 MHz
 # DPMS capabilities: Active off:yes Suspend:yes Standby:yes

 Mode "1280x1024" # vfreq 60.020Hz, hfreq 63.981kHz
  DotClock 108.000000
  HTimings 1280 1328 1440 1688
  VTimings 1024 1025 1028 1066
  Flags "+HSync" "+VSync"
 EndMode
 # Block type: 2:0 3:ff
 # Block type: 2:0 3:fc
 # Block type: 2:0 3:fd
EndSection

[Andreas Schildbach (schildbach)]

This bug is still present on Intrepid RC.