Arch Linux

Psirus

Member

Registered: 2012-01-29

Posts: 45

ATI and DualView

Hi,
I've got an HD6450 card, and two Samsung 223BW monitors. One is connected via DVI, standing on the left, and working nicely. The other is connected via VGA, and doesn't want to play along. On boot, it mirrors the left one, but flickers horribly beyond GRUB. I guess some refresh rate thing. Once I do

xrandr --output VGA-0 --right-of DVI-0

the flickering stops, but I still can't see what is supposed to be there. When I take a screenshot, it looks fine, like I would expect it to look. However, the screen is either completely black, with one row of pixels displaying the mouse cursor if I am at the top of the screen; or: showing a line at the top of the screen with the width of the window that should be there; or: showing a repeated pattern vertical lines on white. The lines have the current border color of xmonad, i.e. I can see whether I have focused the window. I'm not sure what to make of this, or where to start. Thanks in advance for your help.

schmidtbag

Member

From: NH, USA

Registered: 2011-02-08

Posts: 337

Re: ATI and DualView

Which desktop environment are you using, and which drivers?  Also, is this a recent problem or something that only happens to Arch?

Psirus

Member

Registered: 2012-01-29

Posts: 45

Re: ATI and DualView

I'm not using a DE, just xmonad as WM. Currently, it runs on the open source drivers, xf86-video-ati, and I would prefer that because of the incompatibility with the current Xorg, according to the wiki. I don't think this is restricted to Arch, but I was using the propietary drivers under Xubuntu.

schmidtbag

Member

From: NH, USA

Registered: 2011-02-08

Posts: 337

Re: ATI and DualView

Well many DEs have monitor management.  I'll gladly be proven wrong, but without an xorg.conf, proprietary driver tools (such as catalyst or nvidia control panel), or a DE specific screen management tool, I don't think there's a way to get X to know to use both monitors.  There's a possibility your 2nd monitor is actually working but not under the same workspace.  Have you tried doing something like:

export DISPLAY=0.1
xterm

(you can replace xterm with whatever you want).  You could also try 1 instead of 0.1.

Psirus

Member

Registered: 2012-01-29

Posts: 45

Re: ATI and DualView

Well, the dual view is - sort-of - working, I can move windows to the 2nd screen, but it is constantly flickering, and seems to display the "right half" on the left, i.e. what should be the left edge is running straight down the middle; when I move my cursor from the left, working monitor to the right, it shows up in the middle of the screen. So my guess is some refresh rate is just wrong. I've tried playing with Modelines, but so far no luck.

schmidtbag

Member

From: NH, USA

Registered: 2011-02-08

Posts: 337

Re: ATI and DualView

Yeah I'm not entirely sure myself.  Try installing arandr and see if that helps.  It's a nice tool and pretty low on resources but might help configure your screens properly without the trial and error or modelines and refresh rates.

Psirus

Member

Registered: 2012-01-29

Posts: 45

Re: ATI and DualView

I've used the powerstrip program under windows to extract the correct modeline for the monitor…unfortunately, it still flickers and is 'split'. Odd.