Don't forget to kill the klogd and syslogd daemons before you start to debug your driver or kernel codes. Otherwise, your printk will be buffered and you won't know the exact point of crash or hang.
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killall klogd
killall syslogd
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For interrupt handler, the first thing in your ISR is to disable or mask out the interrupt, otherwise, the interrupt may keep firing and your system may be locked up.
At the end of your ISR, you can re-enable and enable the mask of the interrupt.
To get a list of interrupt and interrupt handler,
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cat /proc/interrupts
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