Arch Linux

teras

Member

Registered: 2018-01-28

Posts: 19

Dual monitor setup properly works with xorg but not wayland [SOLVED]

Hello fellow Arch-ians!

I have a problem that drives me mad...
I recently bought a HiDPI monitor and I am trying to make it play nice together with my older monitor.

My old HD monitor is connected to my intel i915 card, while my new HiDPI is connected to my Nvidia card (and unfortunately for reasons beyond my control this couldn't change).

For the HiDPI monitor to properly work, I need to use Wayland. Xorg doesn't support fraction  scale, or DPI per monitor.
The problem is that, under xorg the system properly sees all three monitors, but if I switch to Wayland only the intel monitor is shown.

In the past, since I always needed to connect my monitor to the intel graphics card, I was using bumblebee to have the benefits of both worlds. But now I reverted the changes, uninstalled bumblebee and everything should work - but it doesn't.

So I am a little lost here, I'd like to debug but I don't know how.
Here is also my dmesg if someone  wants to have a look:

https://pastebin.com/jsejA7Ku

Thank you for your help!

Last edited by teras (2018-12-22 01:40:25)

circleface

Member

Registered: 2012-05-26

Posts: 639

Re: Dual monitor setup properly works with xorg but not wayland [SOLVED]

Which Wayland compositor are you using?

Ropid

Member

Registered: 2015-03-09

Posts: 1,069

Re: Dual monitor setup properly works with xorg but not wayland [SOLVED]

You can't really use Wayland with NVIDIA drivers. The last time I checked, Gnome was the only compositor that supported NVIDIA's method to do Wayland, but it didn't work well in practice.

teras

Member

Registered: 2018-01-28

Posts: 19

Re: Dual monitor setup properly works with xorg but not wayland [SOLVED]

Indeed I am using Gnome compositor. The problem for me it seems to be that I somehow have disabled the NVidia card with Wayland with all the changes that accumulated over the years.

I have booted with my Ubuntu partition, which I use only for test purposes, and it seems to work.
I even remembering it to work before making changes for KVM, PCI passthrough, Bumblebee etc.
Now, since it is practically impossible to track down all these changes, I am asking if there is a way to directly ask Wayland why it doesn't use the NVidia card at all.

Just a reminded, it is not recognized at all in Wayland, not only a blank screen.

Thank you

Last edited by teras (2018-12-12 09:51:59)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,627

Re: Dual monitor setup properly works with xorg but not wayland [SOLVED]

To make it recognized for Wayland in any shape or form, you will have to enable KMS on the nvidia card at the very least. This however suffers from various issues that do not make this pleasant or relevantly usable and I'd assume that you'd intend this to be interplaying with a completely different graphics card would further complicate this in a way that simply isn't feasible on Wayland right now, unless maybe using nouveau instead of nvidia if that is an option.

Are you sure that your Ubuntu is running on Wayland? Are you sure the prop drivers are set up there?

Last edited by V1del (2018-12-12 11:47:13)

teras

Member

Registered: 2018-01-28

Posts: 19

Re: Dual monitor setup properly works with xorg but not wayland [SOLVED]

I enabled KMS as you proposed, but with no luck.
Then I changed to nouveau as proposed.

And IT WORKS!

I don't know if indeed the prop drivers can't work, and if there is a way to force them work, but indeed this is not a topic for this forum any more. (And for completeness uner Ubuntu indeed it is using the nouveau drivers).

Thank you for helping me out.

Just a quick question: if I am using AMD, would the situation be better and have better support?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,627

Re: Dual monitor setup properly works with xorg but not wayland [SOLVED]

For this kind of usecase yes, as nouveau still suffers from stability and performance issues for most chipsets it supports, an AMD card would indeed be better given the other constraints of wanting to remain on Wayland. However if the performance of nouveau suffices for your use case, there'd also not be much reason to switch.