I have a very similar issue on RPi4 with Genoo on 64 bits. In my case I can adjust the V3D power control with: /sys/devices/platform/v3dbus/fec00000.v3d/power/control. But it makes no difference setting it to "on" (by default its value is "auto"). I also created the udev rule that was suggested in t...

All the USB problems seems to be fixed on the last 5.4.32 RPi kernel (https://github.com/raspberrypi/linux.git revision 7aace1e16a0c5f34a64eaf3f7f3a511f27a35aa5). After the kernel compilation I restarted the RPi4 and all the USB were back. Here you can check the new lsusb and lspci outputs: # lsusb ...

Same (or very similar) problem here on RPi4 with Gentoo on 64bits. $ dmesg | grep -E "(Linux version|pci|usb|cma)" [ 0.000000] Linux version 5.4.32-raspberrypi-arm64+ (root@pi64) (gcc version 9.3.0 (Gentoo 9.3.0 p1)) #1 SMP PREEMPT Fri Apr 24 15:29:05 CEST 2020 [ 0.000000] OF: reserved mem: initiali...