My Thinkpad X220 doesn't power on the mic led when it's muted. Seems that a patch for this already exists[1], but never got merged. There's also[2]. I did a reserch for existing bugs, but found none. I'd like to see this patch merged or to know why it can't be merged. Free to ask if you need more info. Thank you very much. [1] http://comments.gmane.org/gmane.linux.drivers.platform.x86.devel/1962 [2] https://lkml.org/lkml/2011/8/4/323
Sorry, I just found that this is a bug in Qt instead. The button isn't recognized by Qt. In fact, muting the mic via Alsa correctly shows the led powered on.