Current File : //usr/share/alsa/ucm2/common/ctl/led.conf
#
# Microphone/Speaker LED handling seems like an easy task, but
# the expectations are different:
#
# Main question: Which state should LEDs follow (devices)?
#
# Case 1) set LEDs only for internal resources (speaker/microphone)
# Case 2) set LEDs according the current stream (input/output)
# Case 3) like case 1, but add analog headphones connected to laptop (analog jack)
#
# Discussion for Case 2: It is not possible to handle this in driver
# (kernel). Usually, the sound server knowns the current stream (which may be routed to
# bluetooth or a USB device, for example). Additionally, there is a security flaw if the
# sound server directly controls the LEDs.
#
# Discussion for Case 3: Note that we have currently also USB/Bluetooth headphones which
# do not follow this scenario. In this case, there is no clear LED mapping. It seems
# that this case is somewhat controversional. Thus, analog headphones may be treated as
# an external device.
#
# Result: For safety, simplicity and understable behaviour, only Case 1 should be
# followed - LEDs should respond only to the internal (build-in) speaker output and
# internal (build-in) microphone input in UCM.
#
#
# Macro SetLED - attach or detach speaker or microphone LED to given control element
#
# Arguments:
# LED - LED selection - "speaker" or "mic"
# Action - action for given control - "attach" or "detach"
# CtlId - control identifier (as for amixer, e.g. "Capture Switch" or "name='CaptureSwitch',index=1")
#
DefineMacro.SetLED {
If.0 {
Condition {
Type String
Empty "${var:-SndCtlLedModprobe}"
}
True {
FixedBootSequence [
exec "-/sbin/modprobe snd_ctl_led"
]
Define.SndCtlLedModprobe ok
}
}
If.1 {
Condition { Type AlwaysTrue }
True.FixedBootSequence [
sysw "-/class/sound/ctl-led/${var:__LED}/card${CardNumber}/${var:__Action}:${var:__CtlId}"
]
}
}
#
# Macro CtlNew - helper to create new control elemend
#
# Arguments:
# Arg - string for cset-new
#
DefineMacro.CtlNew.FixedBootSequence [
cset-new "${var:__Arg}"
]
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