Comment 0 for bug 1930629

My raspberry pi 4 running Ubuntu 20.04 server is constantly having trouble the the usb controller.
I have 2 externally powered USB hubs connected that have a few HDDs plugged in.

After a seemingly random amount of time (between 1 minute and 2 days) the usb controller will crash completely. No USB devices are detected anymore after that, i have to reboot the system.

I have tried:
* Providing a lot of cooling (metal case + desktop size fan)
* Switching the USB Hubs to a different brand
* Switching the power supply of the USB hubs
* Switching the power supply of the raspberry

Nothing helped, so i concluded that this probably is a kernel bug. I think the USB controller should not crash at the very least.

I've attached my dmesg.

lsb_release -rd
  Description: Ubuntu 20.04.2 LTS
  Release: 20.04

linux-raspi version: 5.4.0.1035.70

uname -a
  Linux pi 5.4.0-1035-raspi #38-Ubuntu SMP PREEMPT Tue Apr 20 21:37:03 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux

lsusb (after crash)
  Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub