On Tuesday 31 July 2012 17:49:32 Luca Tettamanti wrote:
I'm putting back the CC and adding Alex.
On Tue, Jul 31, 2012 at 5:07 PM, Pali Rohár
pali.rohar@gmail.com wrote:
Thanks, now working. When I write to acpi video brightness file it change brightness and in dmesg is:
[ 47.200998] [drm:radeon_atif_handler], event, device_class = video, type = 0xd0 [ 47.201102] [drm:radeon_atif_get_sbios_requests], SBIOS pending requests: 0x80 [ 47.201104] [drm:radeon_atif_handler], ATIF: 1 pending SBIOS requests [ 47.201105] [drm:radeon_atif_handler], Changing brightness to 11
Great! I'll send an updated patch to Alex soon.
I think that acpi only sent event about brightness key pressed, because nothing happened when I pressed it.
Also for windows is needed special HP application (hp hotkey) for brightness keys. Without it brightness keys not working too...
I've looked at hp-wmi: the hotkey is indeed dispatched via WMI (hp-wmi) so you need something in userspace (KDE, Gnome, etc) to respond to that key press.
No, when I rmmod hp-wmi brightness keys still generate events. And when I disable acpi then brightness keys do not generate events but adjust brightness automatically (by BIOS).
I think that hp-wmi on my notebook only handle bluetooth & wifi rfkills and ALS switch. All button working without hp-wmi too.
And there is one problem with /sys/class/backlight/radeon_bl. When I enable Ambient Light Sensor which auto adjust brightness based on sensor data, writing value 0 (min) or 255 (max) to /sys/class/backlight/radeon_bl/brightness turn off display.
Ok, that's weird. 0 turns off the panel by design, 255 should not...
But when ALS is disabled 0 did not turn display off.
All other values (1-254) are OK (adjust brightness level). When I turn off Ambient Light Sensor (via hp-wmi kernel module) then values 0 and 255 also set brightness level (min and max). My suggestion is to convert value 0 to 1 and 255 to 254 to prevent this problem.
No idea what's going on here... might be some weird vendor magic. The WMI code is rather obscure...
Luca
ACPI/WMI cannot change brightness, see this what doing that ALS function: http://lists.freedesktop.org/archives/dri-devel/2012- March/020416.html