The USB persist feature allows devices that can retain their state when
powered down to work across suspend/resume. This is in particular useful
for USB drives.
However, the persist feature can get in the way for devices that are
unable to retain their state when power is lost. An example of such
stateful devices are fingerprint readers where USB persist should be
disabled to ensure userspace can detect whether the USB device had a
power loss during system suspend.
This will initially be used by the libfprint autosuspend hwdb.
Closes: #20754
Concatenating strings is not a very efficient approach. And in this case fully
unnecessary. We also need some rules to make use of those hwdb entries.
PCI needs to be 8 characters, not 4. And we need to use uppercase hexadecimal
for both. With udev rules this made no difference, but hwdb match is case
sensitive.
Fixes#16119.
