USB autosuspend: exclude serial port devices by default #794
Description
Describe the bug
I own a flea-scope (https://github.com/rtestardi/usbte), and I've been having a weird issue: If USB autosuspend is enabled, the exposed serial port has weirdly broken data transfer. If I connect to the serial port via e.g. minicom and press enter or ctrl+c I can see the activity LED of my scope flashing, meaning, that it's receiving data. The computer however doesn't read any data returning from the device unless I throw minicom at the serial interface the moment it comes up.
I have now figured out that this is due to USB autosuspend, but even with the scope in the denylist I'm still facing the same problem. Turning usb autosuspend off entirely solves this however. Since I don't have any battery power to waste I'd like to keep that enabled however.
I don't know if this is just a weird edge case but it'd probably make sense to add an option to disable suspending of all serial devices altogether since not every serial device is connected to immediately using a udev rule or similar.
Expected behavior
The denylist should have an effect.
To Reproduce
Enable usb autosuspend. Plug in flea-scope, try to connect to it.
Additional context
tlp-stat: https://gist.github.com/UltraBlackLinux/3ea9ce37b97b4c24543a89b82ac0ee5b