If you are using usb devices for longer tasks, like for backups, it could be good to not have them autosuspended after some time, because your backup may fail. To disable usb autosuspend you can do the following:
In file /etc/default/grub add
usbcore.autosuspend=-1
somewhere at the end of the line beginning with GRUB_CMDLINE_LINUX_DEFAULT
This is, how it now looks at my Manjaro Linux system
GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor usbcore.autosuspend=-1 resume=UUID=1c94baec-6ef8-4d19-a671-1adcea387cd5 udev.log_priority=3"
Now update grub with
sudo update-grub
Then reboot and afterwards check, if you have been successful:
cat /sys/module/usbcore/parameters/autosuspend
This should now return -1, default is 2.
Now your usb devices will not automatically suspend any longer.