关于Magic Number 01470C02,大致上搞清楚是怎么回事了。
请看下面一段codec dump
Node 0x14 [Pin Complex] wcaps 0x40018d: Stereo Amp-Out
Amp-Out caps: ofs=0x00, nsteps=0x00, stepsize=0x00, mute=1
Amp-Out vals: [0x80 0x80]
Pincap 0x081003c: IN OUT HP EAPD Detect
Pin Default 0x0221101f: [Jack] HP Out at Ext Front
Conn = 1/8, Color = Black
Pin-ctls: 0x20: IN
Connection: 1
0x0f
请注意红色标注的EAPD,这便是关键所在,
我们来看看spec里面怎么说的
EAPD value is reflected on the EAPD pin; a 1 causes the external amplifier to power up, and a 0 causes it to power down.