目前的问题是声卡出现了，执行如下命令：
root@localhost:~# arecord -d10 -c1 -r22000 -fS16_LE -twav abc.wav
Recording WAVE 'abc.wav' : Signed 16 bit Little Endian, Rate 22000 Hz, Mono
root@localhost:~# cat /proc/asound/card0/pcm0c/sub0/prealloc_max
128
root@localhost:~# cat /proc/asound/card0/pcm0c/sub0/status
closed
root@localhost:~# cat /proc/asound/card0/pcm0c/sub0/hw_params
closed
root@localhost:~# cat /proc/asound/card0/pcm0c/sub0/sw_params
closed
示波器显示12Mhz mclk、 22Khz lrclk、705Khz sclk以及i2c都有在工作，生成的abc.wav文件播放却没有任何声音
mic工作电压一直保持为0.5v
GNU/Linux 3.14.43-g875c69b armv7l
请大神分析一下！感谢
