Hey On Thu, Sep 3, 2015 at 6:14 PM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote: > Hardware manufacturers group keys in the weirdest way possible. This may > cause a power-key to be grouped together with normal keyboard keys and > thus be reported on the same kernel interface. > > However, user-space is often only interested in specific sets of events. > For instance, daemons dealing with system-reboot (like systemd-logind) > listen for KEY_POWER, but are not interested in any main keyboard keys. > Usually, power keys are reported via separate interfaces, however, > some i8042 boards report it in the AT matrix. To avoid waking up those > system daemons on each key-press, we had two ideas: > - split off KEY_POWER into a separate interface unconditionally > - allow filtering a specific set of events on evdev FDs > > Splitting of KEY_POWER is a rather weird way to deal with this and may > break backwards-compatibility. It is also specific to KEY_POWER and might > be required for other stuff, too. Moreover, we might end up with a huge > set of input-devices just to have them properly split. > > Hence, this patchset implements the second idea: An event-mask to specify > which events you're interested in. Two ioctls allow setting this mask for > each event-type. If not set, all events are reported. The type==0 entry is > used same as in EVIOCGBIT to set the actual EV_* mask of filtered events. > This way, you have a two-level filter. > > We are heavily forward-compatible to new event-types and event-codes. So > new user-space will be able to run on an old kernel which doesn't know the > given event-codes or event-types. > > Signed-off-by: David Herrmann <dh.herrmann@xxxxxxxxx> Ping? David -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
