xrandr offers more modes under 12.10 kernel (3.4) as under 12.04 kernel (3.2)

[Dave Chiluk]

It has been discovered that the number of modes available to xrandr in quantal is significantly more than those available in precise. This is especially important in the case where the native resolution of two displays differ, and the displays need to be mirrored. Such as in the case of connecting a laptop to an projector.

$ cat uname-precise.txt
Linux ubuntu 3.2.0-29-generic #46-Ubuntu SMP Fri Jul 27 17:03:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

$ cat xrandr-precise.txt
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 8192 x 8192
LVDS1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 277mm x 156mm
1366x768 60.0 +
1360x768 59.8 60.0
1024x768 60.0*
800x600 60.3 56.2
640x480 59.9
VGA1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 477mm x 268mm
1920x1080 60.0 +
1680x1050 60.0
1600x900 60.0
1280x1024 75.0 60.0
1280x960 60.0
1280x800 59.8
1152x864 75.0
1280x720 60.0
1024x768 75.1 60.0*
1024x576 60.0
832x624 74.6
800x600 75.0 60.3
640x480 75.0 60.0
720x400 70.1
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)

$ cat uname-quantal.txt
Linux ubuntu-ThinkPad-X220 3.5.0-17-generic #28-Ubuntu SMP Tue Oct 9 19:31:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

$ cat xrandr-quantal.txt
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 277mm x 156mm
1366x768 60.0*+
1360x768 59.8 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
VGA1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 477mm x 268mm
1920x1080 60.0 +
1680x1050 74.9 60.0
1680x945 60.0
1400x1050 74.9 60.0
1600x900 60.0
1280x1024 75.0 60.0
1440x900 75.0 59.9
1280x960 60.0
1366x768 60.0*
1360x768 60.0
1280x800 74.9 59.8
1152x864 75.0
1280x768 74.9 59.9
1280x720 60.0
1024x768 75.1 70.1 60.0
1024x576 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
848x480 60.0
640x480 72.8 75.0 60.0
720x400 70.1
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
HDMI3 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)

[Dave Chiluk (chiluk)]

Here's the group of patches that I've identified that attain resolution parity with quantal. I will be sending these out to kernel-team shortly.

[penalvch (penalvch)]

Dave Chiluk, does utilizing the Quantal enablement stack as outlined in https://wiki.ubuntu.com/Kernel/LTSEnablementStack work for you?

[Dave Chiluk (chiluk)]

penalvch, yes the enablement stack should work. The patch set was appropriately rejected by the kernel team, as the enablement kernel would provide the same functionality.

I should have closed this bug out back then when the patchset was rejected.