板载 Realtek ALC888S 音频断断续续，奇怪的是，语音输出正常，但音量较低
Alsamixer 检测到它Realtek ALC1200是Realtek ALC888S
和 lspci：
amith@amith-desktop:~$ lspci|grep Audio
00:09.0 Audio device: NVIDIA Corporation MCP73 High Definition Audio (rev a1)
主板是HP NAPA GL8 G31Core 2 Duo