Code review comment for lp://staging/~manjo/ubuntu/trusty/systemd/HP-m800

Note that a rule can still refer to the general DMI data, like this:

SUBSYSTEM=="input", KERNEL=="event*", SUBSYSTEMS=="platform", KERNELS=="gpio_keys.12", ATTR{[dmi/id]sys_vendor}=="HP*", ATTR{[dmi/id]product_name}=="SuperCalc 100[234]*", ATTRS{keys}=="116", TAG+="power-switch"

So it is easily possible to limit such a rule to particular systems.