Monitor settings are forgotten after external monitor falls asleep and then wakes

Given an nVidia card driving 2 displays (one laptop display, one LCD on DVI), configured for dual display (over and under), the settings are correctly enacted when XFCE first starts from boot, but thereafter, if I suspend the computer and restart, the settings are reset to one monitor (external display).

I have configured the desired settings both in nVidia's control panel and in XFCE's settings, but they are ignored.

I suspect that XFCE is incorrectly assuming the external monitor was just plugged in when the resume happens, and is incorrectly switching to just that monitor.

This *used to work* back on older versions of XFCE, where XFCE didn't try to manage multiple monitors, so only the nVidia driver was handling the issue. Now that XFCE wants to control this, it is broken.

Can you please test this again with xfce4-settings 4.11.3?

Is there a PPA for Ubuntu that I can get that version from (the latest in the normal repos is 4.11.2)

With 4.11.2, the internal display is not disabled completely on resume, but all the programs have been moved to the external display, as if the system had thought it only had the external display, then added the internal display before I could unlock the screen.

You can get the latest git snapshot (4.11.3 + fixes) here:

https://launchpad.net/~xubuntu-dev/+archive/ubuntu/xubuntu-staging

Added the PPA, updated and upgraded XFCE.

The look of the screen setup tool has changed. Unfortunately, the behavior has not.

Setting up the 2 displays (external and internal as over/under), close the laptop lid to suspend, and opening the laptop lid once suspended causes the internal display to be disabled, and only the external display to be used. Re-enabling the internal display places it at a weird location relative to the external display (right and a little above) rather than restoring the original over/under setting.

CONFIRMED. This happens to me on Archlinux using Intel HD 6000 GPU, with dual monitors, one above another.

I'm in the process of setting up an xorg.conf to see if that helps, but Intel GFX usually don't need xorg.conf files.

When the monitors resume I can get XFCE to show a monitor config but the arrangement is now shown in the dialogue options to suit my liking. Would be nice if the system just remembered my settings.

I might make a youtube showing the problem.

Hi! This bug (re)appeared in my freshest Xubuntu! Just upgraded to xenial.
I have "xfce4-settings 4.12.0-2ubuntu1 amd64" (if it matters).

I have 2 displays, one is the laptop's native LVDS1 monitor and other is a HDMI1 monitor (Samsung SyncMaster P2450).
In Settings/Display I configured that only the "Samsung" to be used, i.e. the "Laptop" be disabled. My settings were accepted, everything worked fine.

(Instead of Light Locker, which seems to be buggy, I use gnome-screensaver.)

When I minimize the windows (Super+d), bring up the "Log Out" dialog (Alt+F4) and choose Suspend, the system goes to suspend, okay. When resuming, instead of the HDMI, the LVDS display turns on. Asks for password, and resumes my session - on the laptops's display, instead of the hdmi.
When I go to the Settings/Display, I can see that "somebody" enabled the laptop display and disabled the hdmi.
When I click on the "use this display" below the samsung, the samsung display remains black (off)!
When I click on the same checkbox secondly, then the samsung display switches ON! (In each case, a dialog appears to keep or not this configuration.)

[Please somebody set this bug's status to something other than "needinfo".. It is not the reporter's turn.. It needs attention from somebody else that reporters.]

I found that if in Settings/"Session and Startup" I enable to launch light-locker and disable to launch gnome-screensaver, and before the (first) suspend I issue a locking (Super+L, light-locker) and resume [after which, by side-effect, the unused Laptop display's backlight turns on, erroneously - perhaps I will report it in a separate issue], then the suspend *works*! I.e. after resume from suspend my display settings (which display is enabled and which is not) are not corrupted.
(But, at least some time, the mouse pointer got lost.. :( Nightmare feeling..)

(I have - among others - "lightdm-gtk-greeter 2.0.1-2ubuntu4 amd64" and "light-locker 1.7.0-2ubuntu1 amd64".) (Does it matter?)

So, in short, in the Ubuntu 16.04 (and/or the Xfce4 with it), (among possibly others) the suspending does not work. At least when there are multiple monitors, and/or the user uses other UI-locker than light-locker, and/or the user odes not issue a UI-locking to precede the suspend.

I'm seeing this with:

Xubuntu 17.10
Dell XPS 13 9360 DE laptop
Intel HD 620 GPU
LG 27UD58P-B External monitor connected via Thunderbolt 3 to Display Port cable

Whenever my system suspends or monitor happens to sleep, stand-by, whatever, my settings are not saved, and I am forced to reconfigure everything once again.

xfce4-settings: 4.12.1-1ubuntu1
Linux kernel: 4.13.0-11-generic #12-Ubuntu SMP Tue Sep 12 16:03:57 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

What info is needed?

Similar problem here with XFCE on Gentoo Linux:

The dual head setup of a desktop machine is reset to one mirrored display just by having the monitors switched off for a while. The display is usually locked but the system is running and not sleeping or somehow suspended.

xfce4-session-4.13.0
xfce4-settings-4.13.1
xfconf-4.13.4
xfdesktop-4.13.1
xfwm4-4.13.0-r1

Linux kernel 4.9.58-grsecurity

I guess my bug https://bugzilla.xfce.org/show_bug.cgi?id=12463 is related to this one.

Still have this problem on Arch GNU/Linux:

Kernel: 4.17.14-arch1-1-ARCH

xfce4-session 4.12.1-8
xfce4-settings 4.12.4-1
xfconf 4.12.1-5
xfdesktop 4.12.4-2
xfwm4

I have to log in and out for the monitors to start working again, if I unplug and replug the docking station (or just a screen w/o docking station) the monitors will stop working for the rest of that session. Hitting "enable" in display settings does nothing. Re-plugging cables does nothing.

Created attachment 7992
Proposed fix

This patch adds a '/GlobalSettings/AutoRefresh' boolean in 'displays'. When manually set to false, xfsettingsd ignores monitor plug/unplug events and leaves the displays configuration as-is.