garbled screen with RPI4 on 5.10-rc2

[Lucas Nussbaum]

Hi,

I'm getting a half-garbled screen with an RPI4 on linux 5.10-rc2 (which
includes Maxime Ripard's changes to the VC4 DRM driver).

Photo: https://blop.info/pub/rpi4-vc4.jpg

dmesg output: https://blop.info/pub/dmesg.txt

Including:
[    0.000000] Kernel command line: video=HDMI-A-1:1920x1080M at 60,margin_left=48,margin_right=48,margin_top=48,margin_bottom=48 dma.dmachans=0x71f5 bcm2709.boardrev=0xd03114 bcm2709.serial=0x99e79233 bcm2709.uart_clock=48000000 bcm2709.disk_led_gpio=42 bcm2709.disk_led_active_low=0 smsc95xx.macaddr=DC:A6:32:BE:A2:01 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  console=tty0 console=ttyS1,115200 root=/dev/mmcblk1p2 rw elevator=deadline fsck.repair=yes net.ifnames=0  rootwai

This is with a Debian image from https://raspi.debian.net/, where I just
upgraded the kernel. I also tried updating *.{dat,elf,bin} from
https://github.com/raspberrypi/firmware/tree/master/boot, but it did not
help.

Any ideas?

Thanks!

- Lucas