We are using beagle bone black based custom board, with kernel version 3.12.
We are facing system hang during one of the init script,(Which brings up WiFi)
this hang happens after random number of power cycle,
Nothing works during this hang, it looks like system is frozen, It doesn't even respond to sysrq keys
I assume this to be in the ISR code because of which none of the thing works.
Unluckily When we enable 'Detect hung task(
DETECT_HUNG_TASK)' we don't see the issue. :(
Only thing works is if watchdog is enabled after watchdog timer expires it reboots the system and system recovers.
However we want to find out where the issue is.
I thought of using softdog and repair script pair to print some messages but I assume external interrupt will have higher priority and when it executes and hangs in there, softdog timer will also not get a chance to execute right ?
Randomness of the bug makes it much more difficult to debug :(
Any help appreciated.