Second screen not started, if it is connected before slim starts

monolith · 2013-02-13 11:46:42

I have a problem when using a second screen with a laptop.

My laptop is with a Mobility Radeon HD 6620G video card, and a screen ( "LVDS" ).
The second screen is connected by 15pin VGA cable ( "VGA-0" ).
I use syslinux as boot manager, slim as login manager, and xfce as desktop env.

The driver is xf86-video-ati, and this problems happens after I upgraded to kernel 3.7 .

If second screen is connected before slim starts,
- before slim starts, syslinux and and tty are displayed on both VGA-0 and LVDS.
- when slim starts, LVDS turns to blank, and VGA-0 get turned off ( as if "no signal" )
- I can still switch to tty by ctrl-alt-F1, then VGA-0 lights up, and tty comes back on both

If second screen is NOT connected before slim starts,
- slim is displayed normally on LVDS
- if I plug in the second screen after this moment, it can be started via `xrandr --output LVDS --auto --primary --output VGA-0 --auto --left-of LVDS`, and works normally then.

slim.log, Xorg.0.log in both cases, and output of lspci can be found at https://www.dropbox.com/s/3my9d276p173y … en-log.tgz

Any ideas?

Last edited by monolith (2013-02-13 11:51:10)

Trilby · 2013-02-13 12:37:59

I'm not clear on what the difference is: in either case, X only starts on one screen; in either case, the same xrandr command should get the settings you want.

If you want these settings to be automatic rather than having to call xrandr, then you can set them up in your Xorg.conf.

monolith · 2013-02-13 18:28:24

Trilby wrote:

I'm not clear on what the difference is: in either case, X only starts on one screen; in either case, the same xrandr command should get the settings you want.
If you want these settings to be automatic rather than having to call xrandr, then you can set them up in your Xorg.conf.

Excuse me if I didn't state clearly.

If second screen is connected before slim starts,
- laptop display turns blank
- external monitor turns off as if no signal
- SO X starts on NO screen.

Thanks for the xorg.conf hint. But my another attempt didn't solve that.

If "VGA-0" is ignored like

#/etc/X11/xorg.conf.d/90-vga.conf
Section "Monitor"
         Identifier "VGA-0"
         Option      "Ignore" "true"
EndSection

, LVDS alone works perfectly, except I cannot start VGA-0 with xrandr.

If "LVDS" is ignored instead, external monitor is NOT started, so no display again.

Are there some way to disable but not ignore VGA-0? `Option "Enable" "false"` doesn't do this for me.

Arch Linux

#1 2013-02-13 11:46:42

Second screen not started, if it is connected before slim starts

#2 2013-02-13 12:37:59

Re: Second screen not started, if it is connected before slim starts

#3 2013-02-13 18:28:24

Re: Second screen not started, if it is connected before slim starts

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