Awesome

A terribly-written kext that calls on the Lenovo X250 ACPI method to set the laptop's mute state when the kext's mute state property is changed.

Thanks to RehabMan and Dolnor, this largely consists of their great code cribbed together to make this horrible kext.

Fixer is a misnomer, this is simply a setter.

Having a properly synchronised mute state is useful because:

• it's nice not to have the led and the actual mute state out of sync (happens when the laptop is muted through other means than the physical mute button)

• when the mute state in the laptop's NVRAM is set to mute when shutting down, the BIOS/UEFI beep that happens when you press F2 to enter setup will not occur

I don't recommend using this so only the source is present.

You can tell the kext to set the state with RehabMan's ioio.

I use the following Hammerspoon config which works most of the time:

function ThinkPadMuteLEDFixerClient(mute)
	if mute then
		os.execute("/usr/local/bin/ioio -s ThinkPadMuteLEDFixer MuteStateNVRAM true >/dev/null 2>&1")
	else
		os.execute("/usr/local/bin/ioio -s ThinkPadMuteLEDFixer MuteStateNVRAM false >/dev/null 2>&1")
	end
end


function audioWatch(uid, event, scope, element)
	if (scope == "outp" or scope == "glob") and element == 0 then
		if event == "mute" then
			if dev:muted() then
				ThinkPadMuteLEDFixerClient(true)
			else
				ThinkPadMuteLEDFixerClient(false)
			end
		end
	end
end

dev = hs.audiodevice.findOutputByName("Built-in Output")
if not dev then
	dev = hs.audiodevice.defaultOutputDevice()
end
if dev then
	if dev:muted() then
		ThinkPadMuteLEDFixerClient(false)
		hs.timer.usleep(500000)
		ThinkPadMuteLEDFixerClient(true)
	else
		ThinkPadMuteLEDFixerClient(true)
		hs.timer.usleep(500000)
		ThinkPadMuteLEDFixerClient(false)
	end

	dev:watcherCallback(audioWatch)
	dev:watcherStart()
end