[PLUG] Forcing persistent xrandr display configurations

[Ben Koenig]

The default layout is (most likely) being set via the xrandr front end in MATE. It listens for changes to physical monitor connections and then applies the layout you configured.

Since you are calling xrandr yourself, MATE doesnt know what config to apply. So it picks a sane default.

You might want to see if your preferred layout can be configured via the Display GUI tool. If not, then there are a few other ways to do it manually.

-Ben

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-------- Original Message --------
On May 9, 2022, 2:23 PM, Keith Lofstrom wrote:

> My desktop setup is two largish 1280x1024 rotated
> screens side by side (1024X 1280Y), rotated so the
> narrow tops meet in the middle.
>
> The screens are shared between two computers with
> a KVM switch on the left and a DVI-video-only switch
> on the right. I can only type and mouse into the
> left screen, but I can see what the other computer
> is doing on the right screen.
>
> I've written suid scripts ("twoscreen") in
> /usr/local/bin on both computers that use xrandr to
> set up the screens the way I like. The scripts on
> the two machines slightly different because the
> older two-port-DVI nVidia video cards are different.
>
> The problem is, if a screen is switched to one of
> the computers for a while, the "neglected" computer
> (or X, or the nVidia dual-DVI graphic card) somehow
> decides to rotate the screen image back to "normal",
> which is sideways on the physically rotated screen.
>
> The easiest way to fix this is to make the "twoscreen"
> programs loop in the background, "refreshing" the
> orientation to the desired format every few seconds.
>
> But it is probably cleaner to figure out what bit of
> software or hardware:
>
> (The nVidia graphics driver? X? The hardware of
> the graphics card?)
>
> ... is deciding to ignore prior instructions and
> revert to "normal" orientation without leaving an
> obvious message in Xorg*log or syslog.
>
> Any suggested diagnostics that I can run to learn what
> is triggering the reversion to unwanted "normal" and
> when, while my attention and video is focused on the
> other machine?
>
> If not, I'll just loop the xrandr script in the
> background; kludgy and unclean, but it does the job.
> What could possibly go wrong?
>
> Keith
>
> Note1: one machine is old CentOS7.3, the other is a new
> install of MateUbuntu 20.04 . The goal is to configure
> MateUbuntu 20.04.3 to replace CentOS and duplicate/replace
> DECADES of accumulated linux/unix tools (back to SVR4
> and BSD).
>
> When that is complete, archive the CentOS drive and use
> that machine for long compute jobs. Eventually, that
> secondary machine will be upgraded to MateUbunu 22.04.1
> and the upgrade pingpong will continue indefitely
>
> Note2: I don't need much graphics compute power; if I
> can display a video animation, that's good enough, and
> way less compute power than gaming or real-time video
> synthesis. I wouldn't mind replacing both two-port
> video cards with a cheap low power solution, perhaps
> open-source-friendlier ATI/Radeon; Suggestions?
>
> However, two single-DVI cards in one machine might
> get mixed up by the OS, now or after a future distro
> change. Two port DVI cards seem less difficult to
> goof up.
>
> --
> Keith Lofstrom keithl at keithl.com