I post my experiment and setting as below again.
Linux version 4.1.15-7Dual+gab28f5e (eran@bobo) (gcc version 5.3.0 (GCC) ) #1 SMP PREEMPT Wed Nov 30 19:17:25 IST 2016
HW experiment setting:
Using NB's Headphone plug port as the audio output source then connecting the audio cable plug into Line-in port(J12) of VAR-DVK-MX7.
I use the command as below.(from http://www.variwiki.com/index.php?title ... ecord_play
root@imx7-var-som:~# amixer set 'Capture' 22
root@imx7-var-som:~# arecord -f cd -d 10 -D hw:0,0 test.wav
root@imx7-var-som:~# aplay test.wav
But i can not hear any audio from HP port(J15) via my headset.
Should i set any extra command?
PS:All of setting and method is workable when i use VAR-SOLOCustomboard for testing. So i think my setting, audio cable and NB HW is no problem now.