Xorg external LCD connected to laptop is not recognized
I am using RHEL6 on a Lenovo T410. The internal LCD is defaulting to 1024x768, but after I log in switches to 1280x800, which is correct.
My problem is I have an external LCD that is also connected to it. It's an HP LE2201w that wants 1680x1050. System-config identifies it as "Unknown" and will not allow beyond 1024x768.
Since it's a laptop that isn't always connected to the external LCD, I'm not sure if a manual xorg.conf is the way to go.
Any thoughts on how to fix this?
lspci: 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02) (prog-if 00 [VGA controller])
Responses
Red Hat
Guru
4815 points
Are you connecting the monitor via VGA or Displayport? A colleague of mine is running RHEL 6 on his T410 and I asked him to check connecting it to an external monitor. He connected via VGA and it displayed properly at 1280x1024.
If you are using Displayport it might be worthwhile to try VGA, if only just to see if the problem is specific to one or the other. I'll admit I've never had a system that used Displayport so I'm not sure if there are any special steps to setting it up, but if we can say its specific to that then someone else might have some ideas on how to solve this problem
Red Hat
Guru
1638 points
What does xrandr think the displays can do?
Mine reports this with two screens (Laptop is LVDS1 and external monitor is VGA1)
[mflitter@flits ~]$ xrandr Screen 0: minimum 320 x 200, current 2330 x 1680, maximum 8192 x 8192 LVDS1 connected 1280x800+0+0 (normal left inverted right x axis y axis) 261mm x 163mm 1280x800 60.0*+ 59.8 59.9 50.0 1280x768 59.9 60.0 1024x768 60.0 800x600 60.3 56.2 848x480 60.0 640x480 59.9 VGA1 connected 1050x1680+1280+0 right (normal left inverted right x axis y axis) 459mm x 296mm 1680x1050 59.9*+ 1280x1024 75.0 60.0 1280x960 60.0 1152x864 75.0 1024x768 75.1 70.1 60.0 832x624 74.6 800x600 72.2 75.0 60.3 56.2 640x480 72.8 75.0 66.7 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) DP2 disconnected (normal left inverted right x axis y axis) DP3 disconnected (normal left inverted right x axis y axis)
To set my monitors up I use:
xrandr --output LVDS1 --mode 1280x800 --output VGA1 --mode 1680x1050 --rotate right
so your command would be something like:
xrandr --output <LAPTOP_OUT> --mode 1280x800 --output <EXTERNAL_OUT> --mode <MAX_RES_FROM_XRANDR>
Add --left-of <output> or --right-of <output> to set up screen positions and --rotate <left|right> at your pleasure if portrait screens are your thing!