Several Ubuntu users are reporting this issue:
https://bugs.edge.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/160871
With an ATI 7500, the lcd screen shows 1400x1050, but xrandr offers no other resolutions, although several are supported.
http://launchpadlibrarian.net/12221450/xorg.conf http://launchpadlibrarian.net/12221452/Xorg.0.log
(II) RADEON(0): Printing DDC gathered Modelines: (II) RADEON(0): Modeline "1400x1050"x0.0 108.00 1400 1448 1560 1688 1050 1051 1054 1068 -hsync -vsync (64.0 kHz) (II) RADEON(0): DDC Type: 4, Detected Monitor Type: 2 (II) RADEON(0): EDID data from the display on connector: Proprietary/LVDS ---------------------- (II) RADEON(0): Manufacturer: HTC Model: 17b0 Serial#: 420189172 ... (II) RADEON(0): First detailed timing not preferred mode in violation of standard!(II) RADEON(0): redX: 0.590 redY: 0.340 greenX: 0.320 greenY: 0.560
Looks like it's using DDC instead of EDID, and DDC is only returning the one resolution.
Adding Option "NoDDC" to xorg.conf fixes the issue.
Several Ubuntu users are reporting this issue:
https:/ /bugs.edge. launchpad. net/ubuntu/ +source/ xserver- xorg-video- ati/+bug/ 160871
With an ATI 7500, the lcd screen shows 1400x1050, but xrandr offers no other resolutions, although several are supported.
http:// launchpadlibrar ian.net/ 12221450/ xorg.conf launchpadlibrar ian.net/ 12221452/ Xorg.0. log
http://
(II) RADEON(0): Printing DDC gathered Modelines: ------- ------- -
(II) RADEON(0): Modeline "1400x1050"x0.0 108.00 1400 1448 1560 1688 1050 1051 1054 1068 -hsync -vsync (64.0 kHz)
(II) RADEON(0): DDC Type: 4, Detected Monitor Type: 2
(II) RADEON(0): EDID data from the display on connector: Proprietary/LVDS -------
(II) RADEON(0): Manufacturer: HTC Model: 17b0 Serial#: 420189172
...
(II) RADEON(0): First detailed timing not preferred mode in violation of standard!(II) RADEON(0): redX: 0.590 redY: 0.340 greenX: 0.320 greenY: 0.560
Looks like it's using DDC instead of EDID, and DDC is only returning the one resolution.
Adding Option "NoDDC" to xorg.conf fixes the issue.