Hello Dries and Tilman,

Thank you for providing the logs and other relevant information. For
clarification, when you were testing if the issue still exists, was this
from cold boot or warm boot?

And if you sometimes see it working from cold boot it indeed seems to be very 
racey. There now should be a 100ms power-on-to-good delay on all usb 3.0 hubs 
since 5.4.0-97, which seems like it used to delay whatever race seems to be 
going on when the roothubs are being registered (as per the discussion here 
https://bugzilla.kernel.org/show_bug.cgi?id=214021), but maybe that isn't 
enough to avoid the race in your case?
p.s. If you run lsusb -v as root you should be able to see the bPwrOn2PwrGood 
value of the root hubs as 100ms.

Also, the patchset that seemed to directly address this issue got
reverted due to regressions and never seemed to be re-addressed
upstream... there seem to be a lot of fixes for those introduced
problems since then though so maybe it would make sense to reintroduce
those patches.

I will send an email to the upstream usb mailing list asking about this
and see what their thoughts are.

Thanks, 
- Luke



** Bug watch added: Linux Kernel Bug Tracker #214021
   https://bugzilla.kernel.org/show_bug.cgi?id=214021

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https://bugs.launchpad.net/bugs/1939638

Title:
  [regression] USB device is not detected during boot

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