Raspberry pi Can'；我不能让ALSA在Raspberry Pi上识别我的麦克风softvol控件

我有两个I2S话筒连接到一个Raspberry Pi 3B+running Raspbian（Debian）上。输入电平非常低，因此我需要通过在~/.asoundrc文件中添加softvol控件将其提高约15dB。该文件的内容如下：

pcm.device{
        format S32_3BE
        rate 48000
        type hw
        card memsmic
}

pcm.mic_control {
    type            softvol
    slave.pcm device
    control {
        name        "MemsMic Capture Volume"
        card        memsmic
    }
    max_dB 30.0
    min_dB -3.0
}

pcm.mic_sv {
    type plug
    slave.pcm mic_control
}


pcm.!default{
    type plug
    slave.pcm mic_sv
}

我以前有这个工作，经过多次尝试和错误，但现在我需要重建SD卡，当然它不再工作了。我可以使用以下方法录制音频精细（低电平）：

如果我运行“amixer控件”，我只会得到默认控件：

numid=4,iface=MIXER,name='Master Playback Switch'
numid=3,iface=MIXER,name='Master Playback Volume'
numid=2,iface=MIXER,name='Capture Switch'
numid=1,iface=MIXER,name='Capture Volume'

运行alsamixer并选择mems麦克风作为捕获设备会显示此设备没有控件的信息

arecord-L的输出为：

null
    Discard all samples (playback) or generate zero samples (capture)
jack
    JACK Audio Connection Kit
pulse
    PulseAudio Sound Server
device
mic_control
mic_sv
pulse2
mono
default
    Playback/recording through the PulseAudio sound server
sysdefault:CARD=memsmic
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Default Audio Device
dmix:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Direct sample mixing device
dsnoop:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Direct sample snooping device
hw:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Direct hardware device without any conversions
plughw:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Hardware device with all software conversions
usbstream:CARD=memsmic
    mems-mic
    USB Stream Output

这表明我的文件已被读取为mic_control，mic_sv都已列出

我需要做什么才能让控件显示在ALSA中？我忘记做什么了

null
    Discard all samples (playback) or generate zero samples (capture)
jack
    JACK Audio Connection Kit
pulse
    PulseAudio Sound Server
device
mic_control
mic_sv
pulse2
mono
default
    Playback/recording through the PulseAudio sound server
sysdefault:CARD=memsmic
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Default Audio Device
dmix:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Direct sample mixing device
dsnoop:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Direct sample snooping device
hw:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Direct hardware device without any conversions
plughw:CARD=memsmic,DEV=0
    mems-mic, bcm2835-i2s-ics43432-hifi ics43432-hifi-0
    Hardware device with all software conversions
usbstream:CARD=memsmic
    mems-mic
    USB Stream Output