Using external monitor for a secondary (virtual) desktop view

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yang
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Joined: 04/25/2012

Hello !

I have an issue using an external VGA monitor that is being hooked up to my Laptop. The distribution that I use is Trisquel "toutasis". I tried to set window view using LXDE, Xfce and Gnome, but it doesn't set them as I'd like to (some manuals say that it is doable in Gnome 4.12, but "toutatis" still has ver. 4.8). I would like to use external monitor to display my secondary (virtual) desktop, so that I have a fixed/secondary screen view there where I could run separate applications and not the same mirrored screen view as on my (primary) laptop screen.

So, what I managed to accomplish this far:
Setting resoltuions using "xrandr", using the command:

# xrandr --output VGA-0 --mode 1024x768 --pos 0x0 --rotate normal --output LVDS --mode 1366x768 --pos 0x0 --rotate normal --output HDMI-0 --off

However the above command will only set a full view in my laptop and "partial" view in the external monitor, because external monitor supports 1024x1080, but if I set that resolution for it, I will only have a partial view on my laptop (some screen missing), so it doesn't work as supposed. Now as a result I compensate with a full view in laptop, more than a full view in external monitor.

If anyone is willing to check, I also added an Xorg logfile to http://pastebin.com/jS0Tqgnt
also worth mentioning is that there is no /etc/X11/xorg.conf file at all. I tried manually generating one, but it keeps failing.

# lspci -v |grep VGA
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler [Radeon HD 7340] (prog-if 00 [VGA controller])

Thank you for all suggestions !

Jan

Magic Banana

I am a member!

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Joined: 07/24/2010

I assume you first tried the obvious thing: unclick the related box in "System settings/Display".

You happen to have an AMD video card. It is, among popular brands (i.e., along with Intel and nVidia), the one with the worst support by Linux-libre (some firmware blobs have never been replaced). If your CPU is from Intel, it certainly has an integrated graphical chipset and you had better removed the AMD video card to gain features (such as 3D acceleration), performance and energy!

By the way: neither GNOME 4.8 nor GNOME 4.12 have ever existed! Most of GNOME in Trisquel 6.0 Toutatis is GNOME 3.4.

yang
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Joined: 04/25/2012

Hi Magic Banana !

Mistakenly I entered 4.8 for Gnome, but it is actually Xfce 4.8 and Gnome 3.4 on toutatis, so my mistake.

Regarding the CPU it is a "smpboot: CPU0: AMD E2-1800 APU with Radeon(tm) HD Graphics (fam: 14, model: 02, stepping: 00)"

I was looking in the Gnome options at System settings/Display, but I wasn't able to resolve the issue. I am using linux-libre 3.12 kernel on the laptop.

Regards,
Jan

Magic Banana

I am a member!

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Joined: 07/24/2010

AMD CPUs do not have an integrated graphical chipset.

onpon4
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Joined: 05/30/2012

Hm? AMD CPUs often have Radeon integrated graphics.

yang: If you want a better video card, I suggest the one sold by Think Penguin (It's under Accessories):

http://libre.thinkpenguin.com

yang
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Joined: 04/25/2012

OK, I solved the issue.

To explain:

It was from this manual (I was getting the same error in Gnome/Display settings):
http://askubuntu.com/questions/126392/problem-connecting-multiple-monitors-on-12-04-problema-al-conectar-monitores-ub

But creating virtual area and the xorg.conf file seems to have solved the issue.

Virtual 4096 4096 to the Display Subsection of my /etc/X11/xorg.conf:

SubSection "Display"
Virtual 4096 4096
Viewport 0 0
Depth 24
EndSubSection

Kind regards,
Jan