Re: Blank screen after boot with Radeon HD 5450

Apologies, I have to revise the results from my previous message (by
accident I had the cable connected to the onboard video).

In fact xrandr does detect the DisplayPort connection:

$ DISPLAY=:0 xrandr
Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 8192 x 8192
DisplayPort-0 connected primary 2560x1440+0+0 (normal left inverted
right x axis y axis) 553mm x 311mm
2560x1440 59.95*+
2048x1152 60.00
1920x1200 59.88
1920x1080 60.00 50.00 59.94 30.00 25.00 24.00
29.97 23.98
1920x1080i 60.00 50.00 59.94
1600x1200 60.00
1680x1050 59.95
1280x1024 75.02 60.02
1200x960 59.99
1152x864 75.00
1280x720 60.00 50.00 59.94
1440x576i 50.00
1024x768 75.08 60.00
1440x480i 60.00 59.94
800x600 75.00 60.32
720x576 50.00
720x480 60.00 59.94
640x480 75.00 60.00 59.94
720x400 70.08
DVI-0 disconnected (normal left inverted right x axis y axis)
VGA-0 disconnected (normal left inverted right x axis y axis)

However, the screen remains blank. Changing the resolution doesn't help either:
$ DISPLAY=:0 xrandr --output DisplayPort-0 --mode 1280x720
(screen remains blank)


On Sun, May 28, 2017 at 8:02 PM, Maximilian Pichler
<maxim.pichler@gmail.com> wrote:
> I tried your suggestion of logging in with the keyboard while the
> screen is blank and then typing "startx". Then logged in via ssh:
> $ DISPLAY=:0 xrandr
> Screen 0: minimum 320 x 200, current 1024 x 768, maximum 8192 x 8192
> DisplayPort-0 disconnected primary (normal left inverted right x axis y axis)
> DVI-0 disconnected (normal left inverted right x axis y axis)
> VGA-0 disconnected (normal left inverted right x axis y axis)
>
> The DisplayPort cable is connected.
>
> Still it seems that the problem is not with X, as it occurs even with
> it is disabled.