Am Samstag, 7. Juni 2025, 12:15:48 CEST schrieb Marco Moock: > > I have installed Debian 12.11 using non-free-firmware, > > During the installation, both the internal screen and an external > > HDMI monitor worked, although the internal monitor was rotated by 90°. > > IIRC those displays are portrait type and you need to rotate them in > the OS. The new OS doesn't know that the portrait display isn't mounted > this way. A German blogger also had this issue. > > https://www.danisch.de/blog/2025/04/25/gedrehte-displays/
Great link, seems to be very similar issue and gives some hints on what I could try to experiment with. Thanks! > > > However, when booting the installed system, I see the following: > > Grub menu on both screens, but internal screen rotated by 90° > > After "Loading initial RAM disk", the internal monitor goes blank > > (backlight still on). The HDMI monitor works flawlessly. > > What happens of you boot it up disconnected? Same as with external display connected.... > > > Here is some additional information from the kernel log: > > -------------------------------------------------------------------------- > > 0000:00:16.0-b638ab7e-94e2-4ea2-a552-d1c54b627f04: bound 0000:00:02.0 > > (ops i915_hdcp_component_ops [i915]) [ 89.886760] i915 > > 0000:00:02.0: [drm] *ERROR* hback porch < 16 pixels [ 384.898665] > > i915 0000:00:02.0: [drm] *ERROR* hback porch < 16 pixels > > I think this is the part you should discuss on the mailing list for the > i915 driver. > > > -------------------------------------------------------------------------- > > ----------------------------------- dm@capys:~$ xrandr > > Screen 0: minimum 320 x 200, current 2720 x 1280, maximum 16384 x > > 16384 DSI-1 connected 800x1280+1920+0 (normal left inverted right x > > axis y axis) 0mm x 0mm > > Does it work to change rotation of DSI-1 with xrandr? No, I didn't manage to do that when I booted with "nomodeset" Anway, I will try to continue with the ideas from your link above.
