[Intel-gfx] Intel Driver and 4K video output

[Chris Wilson]

On Fri, Apr 24, 2015 at 03:04:37PM +0200, Lukas Hejtmanek wrote:
> On Fri, Apr 24, 2015 at 01:24:56PM +0100, Chris Wilson wrote:
> > iirc xrandr automatically chooses a fb size for your based on the
> > remaining outputs.
> > 
> > If you add --fb 3840x2160 to each of your invocations, it shouldn't
> > touch the screen size. Hopefully.
> > -Chris
> 
> if you meant something like this:
> xrandr --output eDP1 --off --fb 3840x2160
> 
> then nope, logical screen size is shrunk to 1920x2160. 
> 
> The logical means, that maximizing windows results in a half wide windows and
> the same is for xfce panel. The display is 3840x2160 as expected.

Check panning afterwards? What does xrandr --verbose say before/after?

> Moreover, if I unplug display port cable while eDP1 is off, I don't have any
> screen and it is hard to get at least some display. I thought that this is
> kind of hotplug, i.e., something happens on plug/unplung and that the result
> is different of all black screen. Also, plugging display port cable back does
> not restore display at least on the external monitor, so I have both of them
> black only..

MST is special in this regard as the outputs do disappear. hotplug is
ordinarily handled in userspace (so you need a daemon to restore the
configuration and the X setup should only change due to RandR requests.)
Except that I detect an error and disable unused functions... (And tell
the clients to do something about the new config.) Let's just say we
haven't quite got this perfectly polished yet.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre