# Re: Side effect of pressing special keys

- From: Pali Rohár \<hidden\>
- Date: 2014-12-03 13:24:17 
- List: linux-input
- Page: https://ratatoskr.run/linux-input/2014/12/4387947
- Thread: https://ratatoskr.run/linux-input/2014/11/4380420/t.md

```text
On Wednesday 03 December 2014 14:12:54 Henrique de Moraes 
Holschuh wrote:
> On Wed, 03 Dec 2014, Pali Rohár wrote:
> > Ok, and what about KEY_KBDILLUMTOGGLE when bios also handle
> > keyboard backlight level? Should be this key filtered too?
> 
> IME, heck yes.
> 
> If you ever make the mistake of sending to userspace something
> the BIOS/kernel already reacted to, they will find a way to
> loop it back to you and cause all sort of issues.

Ok, I think same. In KDE4 I see some loop/noop operation when new 
dell keyboard backlight driver is used. Key KEY_KBDILLUMTOGGLE 
cause that BIOS change brightness and also KDE4 see it and change 
it too...

Similar problem there is with KEY_WLAN and NetworkManager.

Gabriele, can you create patch which disable both KEY_WLAN and 
KEY_KBDILLUMTOGGLE in dell-wmi.c driver?

-- 
Pali Rohár
pali.rohar@gmail.com
```

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