Xrandr not enabling external / dual display on boot [SOLVED]

Question

I'm using an HP ProBook 4535s and I want to get a dual display setup working. I've done it before on Ubuntu with this machine and my ASUS external monitor, so I know the hardware supports it.
After I've booted without the external monitor plugged in, if I plug in my VGA-0 and then enter
xrandr --output LVDS --mode 1366x768 --pos 1920x0 --output VGA-0 --mode 1920x1080 --pos 0x0
Then I get perfect resolution on my external monitor, but nothing shows up on my laptop's display. Using arandr also does the job perfectly, but again, it shows nothing on my laptop's display. Additionally, if I try to put a truncated version of the command in xorg.conf, like so,
Section "Monitor"
Identifier "LVDS"
Option "Primary" "true"
Option "PreferredMode" "1366x768"
EndSection
Section "Monitor"
Identifier "VGA-0"
Option "LeftOf" "VGA1"
Option "PreferredMode" "1920x1080"
EndSection
then it starts up the same way (perfect res on external, nothing but backlight on laptop), but it starts in low-graphics mode / seems not to go through any of the commands in .xinitrc. If I try to place the code in .xinitrc, like so,
#!/bin/sh
# ~/.xinitrc
# Executed by startx (run your window manager from here)
if [ -d /etc/X11/xinit/xinitrc.d ]; then
for f in /etc/X11/xinit/xinitrc.d/*; do
[ -x "$f" ] && . "$f"
done
unset f
fi
# Set up dual display (make sure xorg.conf doesn't run before this...)
#xrandr --output LVDS --mode 1366x768 --pos 1920x0 --output VGA-0 --mode 1920x1080 --pos 0x0
# Start xfce4 Desktop Environment
exec startxfce4
# Placed either above or below startxfce4, I get the error described.
#xrandr --output LVDS --mode 1366x768 --pos 1920x0 --output VGA-0 --mode 1920x1080 --pos 0x0
# Bind keys at startup
exec xbindkeys
# Get rid of the annoying warning bell
exec xset -b
# Below is from ~/.bashrc
Then when I boot with the VGA-0 cable in, *nothing* shows up at all. With any of the above configurations aside from the xorg.conf one, I *must* keep the VGA-0 unplugged during boot to get anything to show. I would like to configure my setup so I can always keep the cable in, even during boot. A dynamic setup would be nice, too, so I don't have to fuss with this when I get new monitors, etc.
Also, if it would help, here's the output of lspci | grep VGA:
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Sumo [Radeon HD 6480G]
Thanks,
sirciny
Last edited by sirciny (2013-06-19 14:31:11)

Answer 1

Here's an update: I now have the display spanning both monitors. It shows the right res (1366x768) on the LVDS and the wrong res on the external, and it starts up in low graphics mode. What I did was the following:
1) Install the AMD Radeon HD 6xxxG driver from AMD's website (even though the fglrx is no longer supported in Arch)
2) Copy my Ubuntu partition's xorg.conf to Arch, because Ubuntu's external setup works flawlessly
Of course, the Arch AMD driver is outdated, so I didn't really expect this to work as elegantly as I would like (it still doesn't). Changing it to "intel" in xorg.conf just makes Arch stuck in the TTY when I try to restart X. Here's xorg.conf as it is:
Section "ServerLayout"
Identifier "aticonfig Layout"
Screen 0 "aticonfig-Screen[0]-0" 0 0
EndSection
Section "Module"
EndSection
Section "Monitor"
Identifier "aticonfig-Monitor[0]-0"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
EndSection
Section "Monitor"
Identifier "LVDS"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
Option "PreferredMode" "1366x768"
Option "TargetRefresh" "60"
Option "Position" "0 0"
Option "Rotate" "normal"
Option "Disable" "false"
EndSection
Section "Monitor"
Identifier "CRT1"
Option "VendorName" "ATI Proprietary Driver"
Option "ModelName" "Generic Autodetecting Monitor"
Option "DPMS" "true"
Option "PreferredMode" "1920x1080"
Option "TargetRefresh" "60"
Option "Position" "1280 0"
Option "Rotate" "normal"
Option "Disable" "false"
EndSection
Section "Device"
Identifier "aticonfig-Device[0]-0"
Driver "fglrx"
Option "Monitor-LVDS" "LVDS"
Option "Monitor-CRT1" "CRT1"
BusID "PCI:0:1:0"
EndSection
Section "Screen"
Identifier "aticonfig-Screen[0]-0"
Device "aticonfig-Device[0]-0"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Virtual 3286 1080
Depth 24
EndSubSection
EndSection
Last edited by sirciny (2013-06-18 14:40:52)