xrandr not saving settings permanetly in Ubuntu 14.04

Question

I just installed Ubuntu. I am new to Linux, so I will need this explained in pretty basic terms please. I have two monitors. I use a AMD R7 2xx graphics card. I haven't installed the AMD drivers but don't know if I need to or not. In terminal I used the command xrandr --addmode DVI-0 1600x900 to add that resolution to my second monitor. It works fine until I restart the computer. I read something about needing to change a xorg file in /etc/X11, but that directory doesn't exist on my computer. Not sure what to do.

Solution 1

Personally, I'd add your command xrandr --addmode DVI-0 1600x900 to list of Startup Applications, or create a .desktop file in ~/.config/autostart , so that the command runs on every login.

Solution 2

You can add

display-setup-script=<your_xrandr_command>

to /etc/lightdm/lightdm.conf in [seat defaults] section.

This will ensure it starts before you login into the system.

It also can be done in xorg.conf file, or better in a new file in

/usr/share/X11/xorg.conf.d/<50-some_name.conf>

Comments

[Panther]

You either have to set and save your settings with a graphical tool or run xrandr at login. blog.bodhizazen.net/linux/use-xrandr-to-set-a-screen-resolut‌​ion

[Sergiy Kolodyazhnyy]

@bodhi.zazen fancy ! you even got a blog :)

[Pilot6]

possible duplicate of How can I make xrandr customization permanent?

[Jacob Vlijm]

Note that the command might (and probably will) break if it runs before the desktop is fully loaded. Especially if a second monitor is attached.

[Andrew]

I would, but would that mean I would still get the error window each time I log on. It says: "Could not apply the stored configuration for monitors. Then it says below that could not assign CRTCs to outputs: and a really long list.

[Sergiy Kolodyazhnyy]

@JacobVlijm never had this issue, I've a .desktop file which configures my dual screen with 15.04.

[Jacob Vlijm]

I assure you, in many cases it does, as a result of xrandr to break in that case.

[Andrew]

I will try this now.

[Andrew]

It worked, however, I am still getting this annoying error message when I reboot. It is a long list of CRTC errors. It doesn't seem to affect anything, but it is rather annoying

[Pilot6]

It mast be AFTER [seat defaults], I was wrong before.

[Sergiy Kolodyazhnyy]

@Andrew can't help you with that error, but when you login , try running in terminal xprop and clicking on that error popup or whatever. At least it will tell you what program runs it

[Ravan]

Hi Pilot6, I guess that is /usr/share... , correct?

[Pilot6]

It is correct..