Displaylink

From postmarketOS
Icon WARNING: Currently,Postmarket OS doesn't officially support them.

DisplayLink devices is a type of GPU that allow to connect monitor via usb.

Driver

UDL

udl is kernel module for USB 2.0 DisplayLink devices.It is in the mainline.All postmarket OS's kernel dont have udl kernel module so you need to enable it in the kernel config (DRM_UDL) and recompile the kernel.Also it is quite finicky. Only Some usb 2 displaylink work with it, some dont.(Only HP NL571AA is tested to work.) If your USB 2.0 DisplayLink devices with udl isnt work with udl (For example : evga ev16+), your will get this error from dmesg.

[  228.747008] [drm] vendor descriptor length:e0 data:00 00 00 00 00 00 00 00 00 00 00
[  228.747032] [drm:udl_init [udl]] *ERROR* Unrecognized vendor firmware descriptor
[  228.749618] [drm] Initialized udl 0.0.1 20120220 for 1-1.3:1.0 on minor 1
[  228.749637] [drm] Initialized udl on minor 1
[  228.885058] udl 1-1.3:1.0: [drm] fb1: udldrmfb frame buffer device
[  228.885358] usbcore: registered new interface driver udl

EDVI

edvi is a out of tree kernel module for USB 3 DisplayLink devices.It require proprietary userland components to work .

UI

UDL

Sway/Phosh

  • Cant dual display with internal display of the device
  • Hot plug isnt work
  • If the displaylink is plugged before running sway, sway will only display on the external display. It also will be quite laggy (especially in 3d acceleration).
  • If the displaylink is plugged after running sway, sway will only display on the internal display.

Gnome

44.3 (Wayland) :

Work well (except for small graphics glitch)

45.0 (Wayland) :

Ghosting

Setting system variable CLUTTER_PAINT to disable-clipped-redraws:disable-culling resort this problem

EVDI

See Also

DisplayLink on arch wiki

Displaylink test on oneplus 6t with postmarket os