Dual monitor display does not work when secondary is on the left side

[Obi1Kenobi]

Hi guys,

KUbuntu 10.04 here, 64bit.

I have two identical NVidia cards GT 9400. I have set up XInerama and both monitors are "up". Logged into KDE just fine. The secondary display is physically located to the left of the primary display.

The problem is that if I want to move the mouse on the second screen, as soon as it "gets" there, it starts a "Brownian motion" - it literally jumps in all directions with a very high frequency although all its movements are confined in a roughly 2 inches area. No matter how much I try to move it to the left, it won't go beyond that invisible margin (not that having it in the middle of the secondary screen would help in any way given its oscillating behavior). I can "drag it back" to the primary screen where everything is fine again. Sometimes, not always and not sure exactly when and why, doing this experiment and/or clicking in the secondary screen kills the X server completely and I am back to the login step.

The interesting thing is that is if I configure the secondary screen to be on the "right side", there are no problems - everything works.

Now I know I could physically move the secondary screen to the right ... but the LCDs are slightly different in size (22" versus 23") so it would be great if I should not have to do that.

Likewise I guess I could swap the connectors/cables and thus the monitors roles but the one that's primary now is a better monitor and I need it for gaming ... :-)

If you need anything else let me know. Thank you for reading this !

Best regards,
Obi1

NVIDIA version (as reported by NVidia Settings: 195.36.15). This is a 64bit system.

$ uname -a
Linux 2.6.32-21-generic #32-Ubuntu SMP Fri Apr 16 08:09:38 UTC 2010 x86_64 GNU/Linux
$

$ lspci
00:00.0 Host bridge: Intel Corporation 4 Series Chipset DRAM Controller (rev 03)
00:01.0 PCI bridge: Intel Corporation 4 Series Chipset PCI Express Root Port (rev 03)
00:06.0 PCI bridge: Intel Corporation 4 Series Chipset PCI Express Root Port (rev 03)
00:1a.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #4
00:1a.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #5
00:1a.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #6
00:1a.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #2
00:1b.0 Audio device: Intel Corporation 82801JI (ICH10 Family) HD Audio Controller
00:1c.0 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 1
00:1c.5 PCI bridge: Intel Corporation 82801JI (ICH10 Family) PCI Express Root Port 6
00:1d.0 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #1
00:1d.1 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #2
00:1d.2 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB UHCI Controller #3
00:1d.7 USB Controller: Intel Corporation 82801JI (ICH10 Family) USB2 EHCI Controller #1
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 90)
00:1f.0 ISA bridge: Intel Corporation 82801JIR (ICH10R) LPC Interface Controller
00:1f.2 SATA controller: Intel Corporation 82801JI (ICH10 Family) SATA AHCI Controller
00:1f.3 SMBus: Intel Corporation 82801JI (ICH10 Family) SMBus Controller
01:00.0 VGA compatible controller: nVidia Corporation G96 [GeForce 9400 GT] (rev a1)
02:00.0 VGA compatible controller: nVidia Corporation G96 [GeForce 9400 GT] (rev a1)
03:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8056 PCI-E Gigabit Ethernet Controller (rev 12)
05:03.0 FireWire (IEEE 1394): Agere Systems FW322/323 (rev 70)
$

$ lsb_release -rd
Description: Ubuntu 10.04 LTS
Release: 10.04
$

******************
XORG.CONF - the one giving me headaches
******************

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 1.0 (buildd@yellow) Fri Apr 9 11:51:21 UTC 2010

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 1.0 (buildmeister@builder58) Fri Mar 12 02:12:40 PST 2010

Section "ServerLayout"

# Removed Option "Xinerama" "0"
# Removed Option "Xinerama" "1"
    Identifier "Layout0"
    Screen 0 "Screen0" 1680 0
    Screen 1 "Screen1" 0 0
    InputDevice "Keyboard0" "CoreKeyboard"
    InputDevice "Mouse0" "CorePointer"
    Option "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "InputDevice"

    # generated from default
    Identifier "Mouse0"
    Driver "mouse"
    Option "Protocol" "auto"
    Option "Device" "/dev/psaux"
    Option "Emulate3Buttons" "no"
    Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from default
    Identifier "Keyboard0"
    Driver "kbd"
EndSection

Section "Monitor"
    Identifier "Monitor0"
    VendorName "Unknown"
    ModelName "Samsung SyncMaster"
    HorizSync 30.0 - 81.0
    VertRefresh 56.0 - 75.0
    Option "DPMS"
EndSection

Section "Monitor"
    Identifier "Monitor1"
    VendorName "Unknown"
    ModelName "LEN L2240pwD"
    HorizSync 30.0 - 75.0
    VertRefresh 50.0 - 75.0
EndSection

Section "Device"
    Identifier "Device0"
    Driver "nvidia"
    VendorName "NVIDIA Corporation"
    BoardName "GeForce 9400 GT"
    BusID "PCI:1:0:0"
EndSection

Section "Device"
    Identifier "Device1"
    Driver "nvidia"
    VendorName "NVIDIA Corporation"
    BoardName "GeForce 9400 GT"
    BusID "PCI:2:0:0"
EndSection

Section "Screen"
    Identifier "Screen0"
    Device "Device0"
    Monitor "Monitor0"
    DefaultDepth 24
    Option "TwinView" "0"
    Option "metamodes" "nvidia-auto-select +0+0"
    SubSection "Display"
        Depth 24
    EndSubSection
EndSection

Section "Screen"
    Identifier "Screen1"
    Device "Device1"
    Monitor "Monitor1"
    DefaultDepth 24
    Option "TwinView" "0"
    Option "metamodes" "nvidia-auto-select +0+0"
    SubSection "Display"
        Depth 24
    EndSubSection
EndSection

[Obi1Kenobi (hatespam00-bugrep)]

Hi all,

Was able to find a workaround: I have edited the xorg.conf manually and changed the following lines:

Section "ServerLayout"
[...]
    Screen 0 "Screen0" 1680 0
    Screen 1 "Screen1" 0 0
[...]

with:

Section "ServerLayout"
[...]
    Screen 0 "Screen1" 0 0
    Screen 1 "Screen0" 1680 0
[...]

Basically swapped the "logical" roles in the file.

Also, in the xorg.conf file above, the following line:

Section "ServerLayout"
   Option "Xinerama" "0"

should read:

Section "ServerLayout"
   Option "Xinerama" "1"

Apologize for that mistake.

Hopefully it can helps others while the issue is fixed.

Regards,
Obi1

[Kevin Buley (klb)]

Same issue after upgrade to 10.04, swapping the displays "fixes" it. :/

[Obi1Kenobi (hatespam00-bugrep)]

After latest NVIDIA updated, which happened a few days ago, the issues seemed to have been fixed. At least for me. I fully re-created xorg.conf with "nvidia-settings" and everything works fine. So from my perspective this bug can be closed.

[dino99 (9d9)]

That version is no more supported; please open a new bug report if the actual archive found version also has the same issue.