Re: ThinkPad T480s & LED_MUTE, LED_MICMUTE
From: Henrique de Moraes Holschuh
Date: Fri Jun 15 2018 - 19:36:38 EST
On Fri, 15 Jun 2018, Pali Rohár wrote:
> This means that kernel should not export any led class device. Or when
> exported, then "set" operation should always fail.
"not export" is right.
> > 2. Otherwise implement it in-kernel, so that userspace cannot unmute
> > when the human has activated the "mute" switch, and the LED cannot be
> > controlled by userspace to lie (report mute when it is not mute).
> This looks like a good candidate to use led "trigger" interface. Create
> a mute trigger and attach it to that led device.
Maybe, as long as done in-kernel and not possible to mess with from
> means set. What is SHDA doing, I have not figured out. It does not
Look at the HDA mixer state, SHDA is likely to be directly messing with