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

[Lukas Hejtmanek]

Hello,

not sure whether this list is send-patch-only or for support as well.

However, I have Lenovo X1 Carbon 3rd gen, with 2560x1440 local panel and 4k
(3840x2160) external display connected via display port (directly on X1).

It has Intel HD 5500 graphics.

using xrandr, I can see:

xrandr
Screen 0: minimum 8 x 8, current 2560 x 1440, maximum 32767 x 32767
eDP1 connected 2560x1440+0+0 (normal left inverted right x axis y axis) 310mm x 174mm
   2560x1440      60.0*+
   1920x1440      60.0  
   1856x1392      60.0  
   1792x1344      60.0  
   1920x1200      60.0  
   1920x1080      59.9  
   1600x1200      60.0  
   1680x1050      60.0     59.9  
   1600x1024      60.2  
   1400x1050      60.0  
   1280x1024      60.0  
   1440x900       59.9  
   1280x960       60.0  
   1360x768       59.8     60.0  
   1152x864       60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
DP1 disconnected (normal left inverted right x axis y axis)
DP1-8 connected (normal left inverted right x axis y axis)
   1920x2160      60.0 +
DP1-9 connected (normal left inverted right x axis y axis)
   1920x2160      60.0 +
   1920x1200      59.9  
   1920x1080      60.0  
   1600x1200      60.0  
   1680x1050      60.0  
   1280x1024      75.0     60.0  
   1280x800       59.8  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
DP2 disconnected (normal left inverted right x axis y axis)
DP2-1 connected (normal left inverted right x axis y axis)
   1920x1200      60.0 +
   1920x1080      60.0  
   1600x1200      60.0  
   1680x1050      59.9  
   1280x1024      60.0  
   1280x960       60.0  
   1024x768       60.0  
   800x600        60.3  
   640x480        60.0  
   720x400        70.1  
DP2-2 disconnected (normal left inverted right x axis y axis)
DP2-3 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

So, I suppose, I have to use MST to have 3840x2160. However, how to do it using xrandr?
Is is possible to do it with xrandr 1.4?

xrandr -v
xrandr program version       1.4.1
Server reports RandR version 1.4

I can set auto do DP1-8 output, which works, however, display shows 1920x2160
resolution scaled to the whole screen.

I cannot set auto to DP1-9:

xrandr --output DP1-9 --auto
xrandr: Configure crtc 1 failed

So, is there a way for now to display 4k on the external monitor?

-- 
Lukáš Hejtmánek