Arch Linux

machinedgod

Member

Registered: 2016-03-07

Posts: 24

Laptop issue with external monitors

Hi all,
this is my first post, so please be gentle ;-)

I am recently having issues with my Dell (latitude 3550) laptop when connecting it to external monitors, one connected via HDMI and the other via VGA. Before anything else, I'd like to stress that this *used* to work without problems. I haven't used my external monitor setup in about 3-6 months (I think) so something changed in this period.

When HDMI monitor is connected (1920x1080 60Hz) it shows artifact which looks like an unstable "horizontal swirl", but only in the area below the mouse pointer.
VGA, on the other hand, shuts down as soon as the mouse moves, and after I stop moving it, comes back on after 2-3 seconds.
Laptop display is completely undisturbed in the process.

If I disable or disconnect all displays except a single one - each one works well in isolation. I tested different VGA/HDMI cable and issue persisted, I switched the input on the monitors (they're the same) and it persisted, and I tested with my TV - same problem.

My idea is that it has to do something with video driver and refresh rate. I think my laptop has the Optimus thing, because I use bumblebeed without problems to run Steam games.
X runs on Intel driver - at least this is what glxinfo says when ran without primusrun bridge.

Any idea on how could I resolve this? Thanks.

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,793

Re: Laptop issue with external monitors

Welcome to Arch Linux

I am not going to be able to provide any help -- I use pure Intel graphics on my system.   Which card controls which monitors?  What is the output of lspci -nn   ?
What desktop environment/window manager are you using?   
What is the output of xrandr   ?

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devil_kc

Member

Registered: 2008-09-14

Posts: 93

Re: Laptop issue with external monitors

i've had similar issues with intel and 2 external monitors on laptop. rollback to lts kernel fixed it all.
You can see it here:
https://bbs.archlinux.org/viewtopic.php?id=208427

machinedgod

Member

Registered: 2016-03-07

Posts: 24

Re: Laptop issue with external monitors

Hello,
sorry on not replying sooner - I haven't had chance to take more information from my home computer which exhibits the issue. I will try downgrading the kernel and report, thanks for the tip.