Delay recognizing USB-Drive with Kernel 5.9.12

[thilo]

Hello!
I am new to linux, please excuse false statements :-)).
I think there is a USB_PWR_EN-problem in the kernel (UAS-driver???)
NO            delay recognizing USB-drive with kernel 4.9.247
 >20 sec    delay recognizing USB-drive with kernel 5.9.12

Installed Armbian on SD on an Odroid n2+.
Wanted to move system to USB-SSD, used nand-sata-install.
After that, didn't boot.
New install on SD.
Realized that most of the time it took >20 sec to recognize USB-SSD.
I felt, failing boot was due to slow USB-drive recognition (system drive
not available at boot).

in kern.log:
... localhost kernel: [   33.760038] USB_PWR_EN: disabling
...
... localhost kernel: [  587.836268] usb 1-1.3: new full-speed USB
device number 6 using xhci-hcd

Did some research, found:
https://forum.armbian.com/topic/13580-odroid-n2-kernel49-no-boot-on-usb-sata-ssd/
with:
'BTW what is USB_PWR_EN, are we looking at something interesting here?'
and a link to:
https://forum.armbian.com/topic/11741-boot-from-ssd-with-n2/page/3/
with:
'None ... delay was necessary when using kernel 4.9.x so ... seems ...
problem with the 5.x kernel series, presumably around the UAS driver ...'

With Armbian-config, changed
Kernel 5.9.12 to 4.9.247 (gladly very easy with that!)
After that recognition of USB-SSD was fast.
Another nand-sata-install.
New boot, worked: root part is on USB-SSD!!!

So: problem with 5.x kernel, see top of mail.

Would be glad to get feedback.

Thilo