Re: minidisplay-port on T440s working?

[ng0%n0.is@localhost]

David Brownlee transcribed 2.5K bytes:
> On Thu, 24 Jan 2019 at 15:10, <ng0%n0.is@localhost> wrote:
> 
> > Hi,
> >
> > while the VGA port on my T440s laptop is working, the
> > minidisplay port is not working (at least with an
> > amazonbasics Mini DisplayPort to HDMI cable.
> >
> > With not working I mean: VGA is recognized by xrandr,
> > minidisplayport isn't.
> >
> > Any idea how I can debug this? Has anyone experienced
> > the same issue?
> >
> > This is on NetBSD 8.0 GENERIC / amd64
> >
> 
> I have a T530 (with the dual Intel/Nvidia video chipset) - I suspect it may
> be a slightly different case, but just for reference:

Yeah, it is different - T440s only has an intel GPU chip.
So I'm not sure if this can be compared? I always found dual GPU
enough to avoid as long as I can. 
 
> When I boot with Intel enabled only the VGA port works (also tested with a
> Thinkpad dock which has multiple DVI and other ports, and only the VGA port
> works on that too).
> 
> When I boot with Nvidia enabled the DisplayPort works, but the display
> shows video corruption and rapidly becomes instable.
> 
> Interestingly when I boot Windows with the BIOS locked to Intel only, VGA
> is also the only port that works.
> 
> David