we recently starting deploying our device to a number of test customers. Our device shall sleep (suspend to ram) most of the time, but it can be woken up by SMS and a couple of GPIOs.
While browsing through the logfiles from our test devices, we saw a couple of wakeups which we couldn’t explain. Some colleagues are already starting to blame EMF radiation.
So I was wondering if there is a way to track down the reason for each single wakeup:
- Can Legato notify our application after a wakeup occured?
- Can we query the wakeup reason from Legato or from the kernel then? (I noticed /sys/kernel/wakeup_reasons/last_resume_reason, but it seems to be always empty)
- Is there any kernel debug output we could activate to log the wakeup reason?