OK, so it would be nice if /dev/bus/usb/* would be owned by group lp, then we could have the backend run as user lp again, instead of root. Could folks please try whether this rule makes the printer device owned by root:lp ?
ACTION=="add", SUBSYSTEM=="usb", ATTR{bInterfaceClass}=="07", ATTR{bInterfaceSubClass}=="01", GROUP="lp", MODE="660"
(add it to e. g. /etc/udev/rules.d/cups.rules)
OK, so it would be nice if /dev/bus/usb/* would be owned by group lp, then we could have the backend run as user lp again, instead of root. Could folks please try whether this rule makes the printer device owned by root:lp ?
ACTION=="add", SUBSYSTEM=="usb", ATTR{bInterface Class}= ="07", ATTR{bInterface SubClass} =="01", GROUP="lp", MODE="660"
(add it to e. g. /etc/udev/ rules.d/ cups.rules)