It seems kernel of imx6Q AI board does not support low level debug config, if I enable CONFIG_DEBUG_LL=y, then kernel stuck at some point, fail to boot.
Is there a solution for this issue?
The release I am using is android_jb4.2.2_1.1.0-ga.
try running
make menuconfig
from myandroid/kernel_imx
and enabling kernel hacking.