Comment 4 for bug 1806323

The computer is a dell XPS 9570. Both the internal and external displays are 4K.

I was originally trying this while configured with a single external DP display, connected through the TB16 dock. With that configuration, the external display went totally black, and stayed that way. Today I configured it to also use the internal display, and the symptoms have changed. Results seem to depend on what was most recently configured: internal monitor on/off, display size (HD or UHD), and relative position of the monitors in the Devices control panel.

Note that there is a fixed and reliable delay of 30-60 seconds after the first login until the fwupd service starts up, and the symptoms appear.

KERNEL 4.15.39

Configured with Internal + External display.

Initially both displays go black for about a second or two, then the internal display comes back with a distorted image, which is different depending on the relative geometric positioning of the two displays. Then a second or two after that, the displays go black again, and when they come back on again 1-2 seconds later, they work normally.

Configured with External display only.

Initially the External display goes black. A couple seconds later, the external display comes back on, but now the internal display is also on, with a distorted display. Another delay, and both screens go black again. Then the External display comes back on and operates normally.

KERNEL 4.19 (worse than Kernel 4.15)

Configured with internal + external displays.

Operation is similar to 4.16.

Configured with external display only.

The display goes black and stays that way. However the mouse remains visible and can be moved around the screen.

Note that a USB 2 keyboard and mouse plugged into the docking station do not work at all with kernel 4.19. Both had no issues with Kernel 4.15.