For userspace listens to this key event and reacts appropriately, is it done on gnome-shell? Or any other packages? Thanks! -----Original Message----- From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel Vetter Sent: Friday, July 12, 2013 8:10 PM To: Li, Hao H Cc: intel-gfx at lists.freedesktop.org Subject: Re: Question about how brightness up/down to call the code of xf86-video-intel like intel_output_dpms_backlight etc On Fri, Jul 12, 2013 at 08:53:23AM +0000, Li, Hao H wrote: > Hi > > When we press the key like brightness up/down from keyboard, kernel will receive the keyevent. > My question is how the keyevent from kernel call the code of xf86-video-intel like intel_output_dpms_backlight etc to adjust the backlight. > Can someone help to explain more details about it? Kernel doesn't call the brightness adjustment code. There's a bit of bonghits in acpi where the acpi brightness keys directly adjust the acpi backlight, but that's just not yet been fixed. What's supposed to happen is that userspace listens to this key event and reacts appropriately, e.g. by adjusting the brightness but also by drawing a nice brightness scale on the screen Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch