| 2011-12-22 08:42:08 |
Ketil Malde |
description |
In most cases, 'xrandr --auto' does the Right Thing configuring the avilable displays. However, after I have used the VGA output of my laptop and return to use the HDMI output from my docking station, I get this message:
% xrandr --auto
xrandr: cannot find crtc for output HDMI3
The setup look like this:
% xrandr
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 59.6*+
1360x768 59.8 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
VGA1 disconnected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
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 connected (normal left inverted right x axis y axis)
1680x1050 59.9 +
1280x1024 75.0 60.0
1152x864 75.0
1024x768 75.1 60.0
800x600 75.0 60.3
640x480 75.0 60.0
720x400 70.1
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)
Note that VGA1 is disconnected, but configured with 1024x768. Deconfiguring it works:
% xrandr --output VGA1 --off
% xrandr --auto
This isn't entirely obvious to figure out, and I think --auto should do this (i.e. turn off unused displays to free a crtc) automatically. If this is unacceptable for some reason, I suggest the error message should be changed to be more informative, e.g. something like:
% xrandr --auto
xrandr: cannot find crtc for output HDMI3. VGA1 is currently configured but disconnected, to free its crtc, use 'xrandr --output VGA1 --off'. To share a crtc, configure HDMI3 with the same mode as a configured display.
(This is on a Lenovo X220, but I believe many systems have fewer crtcs than display connections) |
In most cases, 'xrandr --auto' does the Right Thing configuring the avilable displays. However, after I have used the VGA output of my laptop and return to use the HDMI output from my docking station, I get this message:
% xrandr --auto
xrandr: cannot find crtc for output HDMI3
The setup look like this:
% xrandr
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 59.6*+
1360x768 59.8 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
VGA1 disconnected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
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 connected (normal left inverted right x axis y axis)
1680x1050 59.9 +
1280x1024 75.0 60.0
1152x864 75.0
1024x768 75.1 60.0
800x600 75.0 60.3
640x480 75.0 60.0
720x400 70.1
DP2 disconnected (normal left inverted right x axis y axis)
DP3 disconnected (normal left inverted right x axis y axis)
Note that VGA1 is disconnected, but configured with 1024x768. Deconfiguring it works:
% xrandr --output VGA1 --off
% xrandr --auto
This isn't entirely obvious to figure out, and I think --auto should do this (i.e. turn off unused displays to free a crtc) automatically. If this is unacceptable for some reason, I suggest the error message should be changed to be more informative, e.g. something like:
% xrandr --auto
xrandr: cannot find crtc for output HDMI3. VGA1 is currently configured but disconnected, to free its crtc, use 'xrandr --output VGA1 --off'. To share a crtc, configure HDMI3 with the same mode as a configured display.
(This is on a Lenovo X220, with Oneiric, but I believe many systems have fewer crtcs than display connections) |
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