i am working on a 4.14.113 kernel, applying all patches from freescale linux-imx 4.14.78_1.0.0_ga_var01, working on a custom imx6sx board similar to sabresd.
I am experiencing a total kernel hangs around the ext4 rootfs mount. There are no messages useful for debug, no initcall is ongoing, no oops messages, and the freeze point may vary in time, depending if i power cycle fully the board or if i just reset by pwr reset button. If i set a timer in a driver probe, it also stops so the kernel totally freeze.
I finally found out the the issue is caused by CONFIG_CPU_IDLE. Removing it, boot process completes properly, and i reach the prompt. Also, rolling back to kernel 4.9, it works properly with CONFIG_CPU_IDLE enabled.
Considering CONFIG_CPU_IDLE related code may not be the real cause, and that i could have some hw issues too, i am wondering if you know of any imx6sx CONFIG_CPU_IDLE related issue, maybe fixed after 4.14, or if you may know of any similar issue.