Arch Linux

bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Dual Monitor Extend not working

Recently I started getting garbled video out put on my 2 monitors.  Almost like a checkerboard where the video output gets shifted to the right as it goes down.... it doesn't show up on screen shots.

I found that if I unplug or deactivate one monitor there is no issue.  Or if its setup to mirror the displays there is no issue.  I reinstalled xorg and mesa-git.... xrandr detects both monitors correctly.  Not sure what the next troubleshooting steps are.

Thanks

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 74,314

Re: Dual Monitor Extend not working

- desktop environment / display manager?
- compositor?
- hardware / GL driver?
- photo (use your smartphone, please only link the image)
- xorg log
- xrandr output for the broken case

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bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Re: Dual Monitor Extend not working

- desktop environment / display manager?

XFCE / Lightdm

- compositor?

haven't changed on installed anything

- hardware / GL driver?

CPU: AMD Ryzen 5 1600 (12) @ 2.961GHz
GPU: AMD ATI Radeon RX 470/480/570/570X/580/580X/590
Memory: 845MiB / 16021MiB

Driver is xf86-video-amdgpu and mesa-aco-git

- photo (use your smartphone, please only link the image)

Mirrored: https://i.imgur.com/glAFAyX.jpg
Extended: https://i.imgur.com/2dnMPLW.jpg

- xorg log: https://pastebin.com/78dpbbDj

- xrandr output for the broken case: https://pastebin.com/ec7p506n

Last edited by bbarnes1 (2020-04-29 19:53:22)

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 74,314

Re: Dual Monitor Extend not working

The XFCE WM has a built-in compositor. Try to disable it to rule out a bug here.
https://wiki.archlinux.org/index.php/Xf … te_manager

[     9.949] (II) AMDGPU(0): glamor X acceleration enabled on AMD Radeon (TM) RX 480 Graphics (POLARIS10, DRM 3.36.0, 5.6.7-arch1-1, LLVM 10.0.0)

a) does it happen with the vanilla MESA?
b) pass "amdgpu.dc=0 amdgpu.dpm=0 amdgpu.aspm=0 amdgpu.runpm=0 amdgpu.bapm=0" to the kernel
c) does it happen w/ the modesetting driver (remove xf86-video-amdgpu and most likely also the xorg.conf)

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bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Re: Dual Monitor Extend not working

Turning off the compositor fixes it.... but now my pretty transparency is gone...

Are the other steps worth looking into?

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 74,314

Re: Dual Monitor Extend not working

Is there an error if you disable the compositor, alter the layout and then re-enable the compositor?

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bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Re: Dual Monitor Extend not working

If I align my screen either way vertically, the compositor works.

Any horizontal configuration.... the compositor problem comes back

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 74,314

Re: Dual Monitor Extend not working

Do you get the same behavior w/ xcompmgr and/or picom?
(Keeping the xfwm4 compositor disabled)

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bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Re: Dual Monitor Extend not working

I enabled xcompmgr and my terminal window became transparent and no weird behavior. So that appear to work just fine

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 74,314

Re: Dual Monitor Extend not working

Also try picom (iirc xfwm uses an xrender compositor, but they might have switched to a GL implementation) but this looks like a bug in the xfwm compositor so far.

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bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Re: Dual Monitor Extend not working

picom works like xcompmgr

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 74,314

Re: Dual Monitor Extend not working

looks like a bug in the xfwm compositor

https://forum.manjaro.org/t/solved-xfce … ts/98936/8 ?

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bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Re: Dual Monitor Extend not working

I edited .config/xfce4/xfconf/xfce-perchannel-xml/xfwm4.xml to xpresent, restarted, same result

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 74,314

Re: Dual Monitor Extend not working

pacman -Qs libxpresent

Edit, scratch that - seems a hard dep of xfwm4

Last edited by seth (2020-04-30 14:09:09)

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bbarnes1

Member

Registered: 2020-01-05

Posts: 13

Re: Dual Monitor Extend not working

I saw that in the thread, it was installed before I tested