On Wed, 2013-08-07 at 09:44 +0200, Borislav Petkov wrote: > Background is that on my x230, I needed to connect the > Fn-Fx backlight hotkey presses to a script to write to > /sys/class/backlight/intel_backlight/brightness because Fluxbox doesn't > do that (and maybe doesn't have to). > > So, without presuming any ACPI or backlight knowledge, can we make the > backlight control work only in the kernel by connecting the hotkey > presses to some backlight controlling interface which backlight-capable > devices implement so that it works regardless of userspace environment? > Even if the machine is not running X? Not really. The ACPI driver is able to do this because the events and the backlight are associated with the same device. We could potentially make something work with GPU backlight drivers since their PCI device should also be associated with the backlight device, but things get complicated quickly - once ddcci support is hooked up you'll also have kernel backlight devices for some external monitors, and now you need to make a policy decision about which display should be controlled in response to the keypress. One reasonable choice would be whichever display contains the currently focused window, which is obviously out of scope for the kernel. So if we're going to do this then we need a generalised mechanism in-kernel for connecting input devices to backlight devices, and we need a mechanism for disabling it when userspace knows better. This sounds like a lot of work for something that should really just be handled by userspace already. -- Matthew Garrett | mjg59@xxxxxxxxxxxxx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
