[arch-general] External monitors are no longer detected (Intel graphics)

[Oliver Jaksch]

On Tuesday, 2 July 2019, 09:46:02 CEST you wrote:
> On 07/02/2019 01:01 AM, Bennett Piater wrote:
> > Hi,
> > I'm using a Thinkpad T450s with Intel graphics.
> > 
> > Yesterday, I could no longer connect external monitors via miniDP.
> > They were not detected at all, either by xrandr in i3 or by sway
> > (wayland).
> > I didn't have time to dig out a VGA cable and try that, so I cannot rule
> > out physical damage yet - I did try 2 monitors with different cables,
> > both of which work with my wife's Thinkpad.
> > 
> > Since wayland doesn't make a difference, I'm thinking maybe something
> > broke
> > with the (my?) drivers?
> > Is there any other possibility apart from physical damage, and what do I
> > try next?
> > 
> > Cheers,
> > Bennett
> 
> Have you checked the troubleshooting options on
> https://wiki.archlinux.org/index.php/Intel_graphics. I also recall an intel
> issue with recent kernels, but can't put my hand on a link. The problems
> experienced with some are listed in the wiki.

There are *some* issues with intel gpu's and recent kernels. I can't use 
multiple monitors in most of the cases as the i915 module misinterpret 
possible resolutions, for example.

https://bbs.archlinux.org/viewtopic.php?id=246230
https://bugzilla.redhat.com/show_bug.cgi?id=1570392
https://intel-gfx-ci.01.org/cibuglog/open_bugs.html

I'm stuck on aur/linux-lts49 on my Zotac CI547 in the meanwhile as everything 
works there. But better than nothing - or 1024x768 ;)