Following USB ids represent most common generic USB UART Bridges:

10C4:EA60 CP210x UART Bridge
https://usb-ids.gowdy.us/read/UD/10c4/ea60

10C4:EA80 CP2110 HID UART Bridge
https://usb-ids.gowdy.us/read/UD/10c4/ea80

0403:6001 FT232 USB-Serial (UART) IC
https://usb-ids.gowdy.us/read/UD/0403/6001

(There are more such chips and ids)

Many hardware vendors ignore rules and sell their products with this generic
USB ids.

As as result, plugging of such device starts an udev rule fight, which actually
ends by a completely non-functional device.

Actually, these applications fight for these devices:

brttty: Recognizes it as a Braille terminal or display (bug 1092839)
upower: Recognizes it as a Watts Up? Pro
gpsd: Recognizes it as SiRF Star III 20ch Gmouse GPS (or another GPS device for
other ids)
ModemManager: Recognizes it as a modem candidate
argyllcms: Recognized as JETI & KLEIN Spectrophotometer (bug 1007652, already
fixed)

Other packages that might attempt to steal these ids as well (or at least did
it in past):
avrdude: Recognizes it as a AVR programmer
sigrok: Recognizes it as CEM DT-8852, Dangerous Prototypes Buspirate, ChronoVu
LA8, ChronoVu LA16
openocd: Sets it up as a serial bridge to the embedded device (hopefully, only
privileges are set)


Found by:
grep -ir '\(6001\|ea60\|ea80\)' /usr/lib/udev/rules.d /etc/udev/rules.d

If hardware vendors ignore rules and release a device with a USB UART Bridge id
and textual identification, Linux has no chance to recognize the device
plugged.