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UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Dual monitors mirrored, show up as "default", cannot change resolution

After a reboot the monitor settings are broken. I have dual monitors connected via (edit) HDMI. xfce4-display-settings shows just one monitor labeled "default", and all of the settings have just one option so nothing can be altered. The desktop is mirrored to both screens.

The settings for the "real" monitors are still stored in ~/.config/xfce4/xfconf/xfce-perchannel-xml/displays.xml:

<?xml version="1.0" encoding="UTF-8"?>

<channel name="displays" version="1.0">
  <property name="Default" type="empty">
    <property name="DP-1" type="string" value="1. Ancor Communications Inc 23&quot;">
      <property name="Active" type="bool" value="true"/>
      <property name="Resolution" type="string" value="1920x1080"/>
      <property name="RefreshRate" type="double" value="60.000000"/>
      <property name="Rotation" type="int" value="0"/>
      <property name="Reflection" type="string" value="0"/>
      <property name="Primary" type="bool" value="true"/>
      <property name="Position" type="empty">
        <property name="X" type="int" value="0"/>
        <property name="Y" type="int" value="0"/>
      </property>
    </property>
    <property name="DP-2" type="string" value="2. Ancor Communications Inc 23&quot;">
      <property name="Active" type="bool" value="true"/>
      <property name="Resolution" type="string" value="1920x1080"/>
      <property name="RefreshRate" type="double" value="60.000000"/>
      <property name="Rotation" type="int" value="0"/>
      <property name="Reflection" type="string" value="0"/>
      <property name="Primary" type="bool" value="false"/>
      <property name="Position" type="empty">
        <property name="X" type="int" value="1920"/>
        <property name="Y" type="int" value="0"/>
      </property>
    </property>
    <property name="default" type="string" value="default">
      <property name="Active" type="bool" value="true"/>
      <property name="Resolution" type="string" value="1920x1080"/>
      <property name="RefreshRate" type="double" value="77.000000"/>
      <property name="Rotation" type="int" value="0"/>
      <property name="Reflection" type="string" value="0"/>
      <property name="Primary" type="bool" value="false"/>
      <property name="Position" type="empty">
        <property name="X" type="int" value="0"/>
        <property name="Y" type="int" value="0"/>
      </property>
    </property>
  </property>
  <property name="Notify" type="bool" value="true"/>
</channel>

I have tried uninstalling and reinstalling the driver xserver-xorg-video-intel. I don't really know what to try next, any help is greatly appreciated!

Last edited by UrbanGrill (2017-06-10 10:46:26)

ToZ

Administrator

From: Canada

Registered: 2011-06-02

Posts: 11,492

Re: Dual monitors mirrored, show up as "default", cannot change resolution

Hello and welcome.

What version of Xfce are you using? Which distro?

Were any of the Xfce packages just recently updated? If so, which ones?

One of the things that you can try is, while not logged in, rename the ~/.config/xfce4/xfconf/xfce-perchannel-xml/displays.xml. A new one will be generated on the next log in.

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UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Re: Dual monitors mirrored, show up as "default", cannot change resolution

Xfce version 4.12, Xubuntu 17.04.

As far as I can see in the /var/log/apt/history* logs, all the xfce4 packages were installed when the computer was set up on Apr 12. After that, unattended-upgrade has run regularly but no xfce4 packages have been upgraded. I am not sure when I rebooted last; it was probably over a month ago.

I tried booting into single-user mode and renaming displays.xml. The generated file only contains the "default" monitor, the DP monitors are gone. I should mention that there are two desktop users on this machine and the monitor issue affects both users.

Last edited by UrbanGrill (2017-06-10 10:46:48)

UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Re: Dual monitors mirrored, show up as "default", cannot change resolution

Output from lspci:

$ lspci -k | grep -A2 VGA
00:02.0 VGA compatible controller: Intel Corporation Device 5916 (rev 02)
	DeviceName:  CPU
	Subsystem: Intel Corporation Device 2068

UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Re: Dual monitors mirrored, show up as "default", cannot change resolution

Checking the displays.xml for the second user on this machine, the "default" monitor entry is not present, just DP-1 and DP-2. I think the "default" monitor is added by xfce4-display-settings when saving the configuration.

UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Re: Dual monitors mirrored, show up as "default", cannot change resolution

I found an Ubuntu user with the same problem, no solution: https://askubuntu.com/questions/833732/ … raphics-dr

I am guessing that this is not an issue with Xfce, but an Ubuntu problem.

UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Re: Dual monitors mirrored, show up as "default", cannot change resolution

I have compared the Xorg logs from before and after, and the old log has a section where DP-1 and DP-2 are discovered, which is missing in the new (failing) log:

[2064873.867] (II) Loading sub module "glamoregl"
[2064873.867] (II) LoadModule: "glamoregl"
[2064873.869] (II) Loading /usr/lib/xorg/modules/libglamoregl.so
[2064873.886] (II) Module glamoregl: vendor="X.Org Foundation"
[2064873.886] 	compiled for 1.19.3, module version = 1.0.0
[2064873.886] 	ABI class: X.Org ANSI C Emulation, version 0.4
[2064873.886] (II) glamor: OpenGL accelerated X.org driver based.
[2064873.907] (II) glamor: EGL version 1.4 (DRI2):
[2064873.908] (II) modeset(0): glamor initialized
[2064873.910] (II) modeset(0): Output DP-1 has no monitor section
[2064873.924] (II) modeset(0): Output DP-2 has no monitor section
[2064874.051] (II) modeset(0): Output HDMI-1 has no monitor section
[2064874.054] (II) modeset(0): EDID for output DP-1
[2064874.054] (II) modeset(0): Manufacturer: ACI  Model: 24c3  Serial#: 66086
[2064874.054] (II) modeset(0): Year: 2014  Week: 45
[2064874.054] (II) modeset(0): EDID Version: 1.3
[2064874.054] (II) modeset(0): Digital Display Input
...

I can post the content of the Xorg logs, if anyone knows how to read them.

ToZ

Administrator

From: Canada

Registered: 2011-06-02

Posts: 11,492

Re: Dual monitors mirrored, show up as "default", cannot change resolution

Perhaps it's a graphics driver issue then with a recent update. Can you try downgrading your intel video driver to see if that helps?

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UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Re: Dual monitors mirrored, show up as "default", cannot change resolution

I even uninstalled the Intel display driver without any luck.

UrbanGrill

Member

Registered: 2017-06-09

Posts: 8

Re: Dual monitors mirrored, show up as "default", cannot change resolution

Successful Xorg log contains:

[2064873.339] (II) xfree86: Adding drm device (/dev/dri/card0)
...
[2064873.865] (**) modeset(0): claimed PCI slot 0@0:2:0
[2064873.865] (II) modeset(0): using default device
...
[2064873.867] (II) modeset(0): Creating default Display subsection in Screen section

And then the setup of the screens is done by modeset.

Unsuccessful log contains:

...
[    26.023] (EE) open /dev/dri/card0: No such file or directory
[    26.023] (WW) Falling back to old probe method for modesetting
[    26.023] (EE) open /dev/dri/card0: No such file or directory
...
[    26.024] (**) FBDEV(1): claimed PCI slot 0@0:2:0
[    26.024] (II) FBDEV(1): using default device
...
[    26.024] (EE) Screen 0 deleted because of no matching config section.
[    26.024] (II) UnloadModule: "modesetting"
[    26.024] (II) FBDEV(0): Creating default Display subsection in Screen section

And then the setup of the screens is done by fbdev, which apparently does not work. The line "xfree86: Adding drm device (/dev/dri/card0)" seems to be important. This is where the logs start to differ.

I think this page contains some hints, but it is very opaque unless you are a seasoned kernel hacker.
https://wiki.gentoo.org/wiki/Intel#Kernel

Last edited by UrbanGrill (2017-06-10 20:40:08)