Dual monitor (w/laptop): external monitor is blank.

Mamsaac · 2012-03-16 11:20:46

Hi! just installed arch for the first time a day ago. Right now what I'm working on is on getting my second monitor running (mostly for development purposes... and movies ^__^).

I'm using Arch64 with the open ATI driver and KDE. Whenever I connect the external monitor, the monitor seems to detect a connection occurred (the "check video cable" message disappears when I connect it and comes back when I disconnect it), and so does KDE. When I open my display settings, it tells me a new monitor was connected and asks me if I want to configure it.

Then I choose to configure and use the two monitors giving the following screens (right now I'm at college testing with monitors in there, thus the low resolution, but behavior seems to be exactly the same):

(EDIT: resized. In case of wishing to read full images, just take the "resized/" out of the URI)
However pretty the full screenshot looks like (... I just mean that even if it looks like the second monitor is working), the monitor remains blank.

Using arandr (xrandr's gui), it is exactly the same result. I might be doing something wrong (almost certainly I am ) (EDIT: decided it was a good idea to show what I did with xrandr).

In /home/<myuser>/.xinitrc my file looks like this:

#!/bin/sh
#
# ~/.xinitrc
#
# Executed by startx (run your window manager from here)
xrandr --output VGA-0 --mode 1440x900 --pos 1600x0 --rotate normal --output LVDS --mode 1600x900 --pos 0x0 --rotate normal --output HDMI-0 --off
if [ -d /etc/X11/xinit/xinitrc.d ]; then
  for f in /etc/X11/xinit/xinitrc.d/*; do
    [ -x "$f" ] && . "$f"
  done
  unset f
fi

exec ck-launch-session startkde
# exec gnome-session
# exec startkde
# exec startxfce4
# ...or the Window Manager of your choice

The laptop's model is Toshiba Satellite L775d. I'm not sure what other information should be required in this situation, but I will be loving to give anything that isn't compromising

Thank you!

(PS: so far Arch has treated me nicely let's see for how long)

Last edited by Mamsaac (2012-03-16 12:24:27)

Spider.007 · 2012-03-16 11:50:39

What is the output of just 'xrandr'? It will confirm the resolutions and refresh-rates supported by the external monitor. Also, I wonder if KDE interferes (or maybe uses) xrandr. It might not be a good idea letting two apps try to configure your monitors using possible different solutions

Mamsaac · 2012-03-16 12:07:12

Thank you for your response!

# xrandr                                                                                                                                                                                   
Screen 0: minimum 320 x 200, current 3040 x 900, maximum 8192 x 8192
VGA-0 connected 1440x900+1600+0 (normal left inverted right x axis y axis) 410mm x 256mm
   1440x900       59.9*+
   1280x1024      75.0     60.0  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   832x624        74.6  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
LVDS connected 1600x900+0+0 (normal left inverted right x axis y axis) 382mm x 214mm
   1600x900       60.1*+
   1440x900       59.9  
   1280x854       59.9  
   1280x800       59.8  
   1280x720       59.9  
   1152x768       59.8  
   1024x768       59.9  
   800x600        59.9  
   848x480        59.7  
   720x480        59.7  
   640x480        59.4

I wondered the same. I initially only used KDE for it (that's how it worked in other distros, but I'm guessing Fedora and Kubuntu have way more stuff on top). I moved to xrandr later after searching for options and I did select "Ignore" when KDE asked me to configure and just went ahead with xrandr. The same still happens.

Thanks, I hope I gave the right information.

EDIT: Adding some extra information. I tried rebooting with the CRT cable connected. When the kernel initiated its loading, the messages only appeared on the external monitor. It was afterwards (it was pretty quick, but I will assume it was when radeon's modeset hit) that the external monitor went blank again and, in that situation, the laptop's monitor went blank (so none of the two monitors worked... and I was so hopeful!)

Last edited by Mamsaac (2012-03-16 12:14:51)

Earnestly · 2012-03-16 12:13:24

Just a heads up: https://wiki.archlinux.org/index.php/Fo … s_and_Code

Do not post full screen pictures; use thumbnails instead. Any image with dimensions greater than 250x250px or over 50Kb in size will be removed.

Mamsaac · 2012-03-16 12:16:49

Sorry, I didn't read that... and I don't have any image editor at the moment. I will install kolourPaint and fix it right away.

EDIT: Done. I think 250x250 as max-limit seems a bit too low... but I guess I should just adapt

Last edited by Mamsaac (2012-03-16 12:25:21)

Spider.007 · 2012-03-17 12:28:32

Mamsaac wrote:

Sorry, I didn't read that... and I don't have any image editor at the moment. I will install kolourPaint and fix it right away.
EDIT: Done. I think 250x250 as max-limit seems a bit too low... but I guess I should just adapt

You can put [ URL ] tags around you image to link them to the full size, might be useful for some people

Reading your update it might be that KMS is indeed to blame, did you look at https://wiki.archlinux.org/index.php/Ra … ooting_KMS to see if disabling KMS might fix this?

Last edited by Spider.007 (2012-03-17 12:28:45)

Arch Linux

#1 2012-03-16 11:20:46

Dual monitor (w/laptop): external monitor is blank.

#2 2012-03-16 11:50:39

Re: Dual monitor (w/laptop): external monitor is blank.

#3 2012-03-16 12:07:12

Re: Dual monitor (w/laptop): external monitor is blank.

#4 2012-03-16 12:13:24

Re: Dual monitor (w/laptop): external monitor is blank.

#5 2012-03-16 12:16:49

Re: Dual monitor (w/laptop): external monitor is blank.

#6 2012-03-17 12:28:32

Re: Dual monitor (w/laptop): external monitor is blank.

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