Follow-on question for David H: I'm in the process of preparing a detailed writeup on this issue for Raymond over on the kernel bugtracker (ticket #96171). There are a lot of moving parts to it, and I want to make sure the details are stated correctly there to avoid unintentionally sending Raymond on a wild goose chase. So I want to ask your indulgence in clarifying one small point on something you mentioned earlier, to make certain that I have a clear understanding: "[T]he mute LED reflects the state of the Master Playback Switch. Any discrepancy of the above would be a kernel bug." The attached screenshot shows how I experimented with this, and what was observed: Regardless of which output Port (speaker or headphone) is selected on pavucontrol, the ALSA Master Playback mute state indicator ("MM" or "OO") follows the mute state shown on pavucontrol: When the pavucontrol mute icon is toggled, the "MM/OO" mute indicator on the ALSA Master Playback also toggles accordingly. However, the mute LED always remains off. (And all of the above also holds if "pactl set-sink-mute 0 toggle" is substituted for clicking the pavucontrol mute icon.) So the question is: Is the state of "Master Playback Switch" that you referred to in your response above indeed represented by the "MM/OO" display on the ALSA Master Playback slider, as I've assumed? If so, then it seems like this is clear-cut evidence that the mute LED is not behaving as expected. Thanks! -------------- next part -------------- A non-text attachment was scrubbed... Name: mute_exp2.png Type: image/png Size: 90286 bytes Desc: not available URL: <http://lists.freedesktop.org/archives/pulseaudio-discuss/attachments/20150413/fcbec641/attachment-0001.png>