Problems Reading Accelerometer Device

Werner Almesberger werner at
Wed Nov 26 13:39:27 CET 2008

Andy Green wrote:
> Probably nothing, some other driver with higher interrupt priority can
> be blocking service for 30ms enforcing latency... not sure what to
> recommend about identifying which one unfortunately.

A 30ms interrupt handler would be pretty evil :-(

My find-irq-blockers.patch could be adapted to monitor the time
interrupt handlers spend doing their thing, by adding the
intrumentation not to disable/enable pairs but to handle_IRQ_event.

Another thing to consider are paths that involve a workqueue.
Since lots of things get sent to workqueues these days, you may
end up sharing it with something that takes a very long time to

- Werner

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