Dell XPS 13 2020 hang on boot with rainbow pattern
I use Fedora 33 on a Dell XPS 13 (2020). Fedora recently started using the 5.9 kernel. That broke my setup. At boot, the video produces a rainbow pattern (see attached image). This appears before the point at which I'd usually start entering in the password for my encrypted drive. After about 15 seconds, the boot fails, and the machine switches off.
Kernel is 5.9.8-200.fc33.x86_64.
inxi -Fmxz output:
Graphics: Device-1: Intel UHD Graphics vendor: Dell driver: i915 v: kernel bus ID: 0000:00:02.0 Device-2: Microdia Integrated_Webcam_HD type: USB driver: uvcvideo bus ID: 3-6:3 Display: server: Fedora Project X.org 1.20.9 driver: i915 note: display driver n/a resolution: 1920x1200~60Hz OpenGL: renderer: Mesa Intel Xe Graphics (TGL GT2) v: 4.6 Mesa 20.2.2 direct render: Yes