External monitor scrolling huge virtual buffer with laptop monitor

[Herbert]

- Dell XPS 14Z
- NVidia GeForce GT 520M + Intel i915
- nvidia-prime
- Mini-DP connected to DVI of external HP LP2065 monitor
- Ubuntu 14.04
- nvidia 331 drivers (from Ubuntu repos)

If my external monitor is located at top of laptop screep:
- when I move the mouse cursor to the bottom of the external screen, it scroll the entire screen to show the laptop screen inside the external monitor, just like a huge virtual screen.

If my external monitor is located at right. everything is fine, there is no scrolling.

I'm not sure this is a bug. I searched the web and could not find a way to properly fix this. Since the behavior change with the sideways arrangement I guess is a bug.

[Herbert (herbert-fischer)]

Here is the output of xrandr:

============================
$ xrandr
Screen 0: minimum 8 x 8, current 2966 x 1200, maximum 16384 x 16384
DP-0 connected primary 1600x1200+1366+0 (normal left inverted right x axis y axis) 408mm x 306mm
   1600x1200 60.0*+
   1280x1024 85.0 75.0 60.0
   1280x960 60.0
   1024x768 85.0 75.0 60.0
   800x600 85.1 60.3
   640x480 85.0 75.0 59.9
DP-1 disconnected (normal left inverted right x axis y axis)
LVDS1 connected 1366x768+0+432 309mm x 174mm
   1366x768 60.0*+ 40.0
   1360x768 59.8 60.0
   1024x768 60.0
   800x600 60.3 56.2
   640x480 59.9
VGA1 disconnected
HDMI1 disconnected
DP1 disconnected
VIRTUAL1 disconnected
  1024x768 (0x2be) 65.0MHz
        h: width 1024 start 1048 end 1184 total 1344 skew 0 clock 48.4KHz
        v: height 768 start 771 end 777 total 806 clock 60.0Hz
  800x600 (0x2c0) 40.0MHz
        h: width 800 start 840 end 968 total 1056 skew 0 clock 37.9KHz
        v: height 600 start 601 end 605 total 628 clock 60.3Hz
  640x480 (0x2c3) 25.2MHz
        h: width 640 start 656 end 752 total 800 skew 0 clock 31.5KHz
        v: height 480 start 490 end 492 total 525 clock 59.9Hz
============================

[Herbert (herbert-fischer)]

Sorry. The xrandr output in #2 is using a sideways placement and have no panning/scrolling issue.

[Herbert (herbert-fischer)]

Using a top-bottom setup, xrandr displays that there is panning configuration. I've tried disabling it but got an error from xrandr.

[DavidWhyte (david-whyte)]

#1312275 and this seem to be duplications of each other.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[DavidWhyte (david-whyte)]

Just to confirm, I get the exact same behaviour when the external screen is placed to the left. The external display pans to duplicate the desktop of the built in display. Also, maximising windows causes the window to span across both monitors.