Re: [PATCH] Revert "ALSA: hda - Add mute-LED mode control to Thinkpad"

[Takashi Iwai <tiwai@suse.de>]

At Mon, 25 May 2015 14:44:04 +0800,
Raymond Yau wrote:
> 
> >
> > This reverts commit 7290006d8c0900c56d8c58428134f02c35109d17.
> >
> > Through the regression report, it was revealed that the
> > tpacpi_led_set() call to thinkpad_acpi helper doesn't only toggle the
> > mute LED but actually mutes the sound.  This is contradiction to the
> > expectation, and rather confuses user.
> >
> > According to Henrique, it's not trivial to judge which TP model
> > behaves "LED-only" and which model does whatever more intrusive, as
> > Lenovo's implementations vary model by model.  So, from the safety
> > reason, we should revert the patch for now
> 
> Are there any ThinkPad which known to support mute led through ACPI SSMS ?

The answer is "yes, but..."

There are known Thinkpads that do the audio mute together with LED.
And judging the difference isn't trivial.  It'd need a huge
black/white list, which we want to avoid.


Takashi