Arch Linux

blubbb

Member

Registered: 2013-09-26

Posts: 59

[Update] No signal from keystroke

Hello Guys

All of sudden I can't raise or lower my screen brightness via the media key anymore. Sometimes it works, but most times it wont. When I ran xev and pressed the corresponding keys(Thinkpad x230t so it's fn+f8 which produces the XF86MonBrightnessUp event) didn't produce the event, they produced NO event at all(except once or twice the XF86WakeUp[fn key himself]). Sometimes it works, but mostly not.
What drives me crazy is that in Windows it works flawless.(I do have a windows partition on my laptop)

So could any wizard help me further?

Best regards
Blubbb

Update: Ok, there definitly IS a keystroke signal however it's rather strange: Whenever changing the brightness won't work via the keys, in the moment I type acpi in the console all the changes that should have been done will immediatly take place. So if I hit 7x raise brightness nothing happens and then enter acpi in the console, the brightness will be raised 7 times.
That behaviour was observed on Xmonad using a very basic config file which only changes the mod key and adds volume and brightness keys(a stroke from the brightness key spawns xbacklight +/-20.(As stated above, sometimes it works normally, but mostly not)

Last edited by blubbb (2014-01-03 07:50:22)

martinled

Member

Registered: 2012-12-23

Posts: 5

Re: [Update] No signal from keystroke

Hi, I have the same problem but with a system76 galago (KDE desktop). fn+f8 and fn+f9 are correctly detected as  XF86MonBrightnessUp/Down events, but screen brightness does not change.

Note that I can manually change the backlight with the /sys/class/backlight/acpi_video0 file.

Thanks,
Martin

martinled

Member

Registered: 2012-12-23

Posts: 5

Re: [Update] No signal from keystroke

I solved the problem by adding :

acpi_backlight=vendor

to the kernel line in /boot/grub/grub.cfg

Hope it will work for you too.
Martin

blubbb

Member

Registered: 2013-09-26

Posts: 59

Re: [Update] No signal from keystroke

hm, for me it's rather strange, the last two days I didn't have any occurences of this bug. So hopefully solved...