Hi All, I was annoyed by the kbd-backlight on my Dell XPS 9550 not working well together with the GNOME3 ui for kbd-backlight control. Part of the problem here is that the hotkey on the laptop's keyboard to control the kbd backlight is fully handled in firmware. So dell-wmi does not send any key-presses for it. This is the right thing todo since sending such key-presses will result in userspace adjusting the backlight, while this has already been done by the firmware. OTOH userspace should really still get some sort of event when this happens, just like e.g. on some systems with hardwired volume-up/down buttons the alsa mixer interface will send events to notify userspace about the changed volume. Checking other sysfs drivers, there is a standard way to notify userspace about changes to a sysfs attributes underlying value. This patch-set adds a led_notify_brightness_change led-core function using this standard mechanism and makes the dell-wmi driver call led_notify_brightness_change on the kbd_backlight led_classdev when the firmware has changed the brightness. Together with some userspace changes / fixes this leads to a much nicer / more integrated experience wrt kbd backlight control. Currently this patch-set introduces only 1 user (dell-wmi) of the new led_notify_brightness_change function, but I plan to also fix the same issue on thinkpads (soon), and also one some HP models (when I can borrow one, hopefully also soon). Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
