On Tue, Sep 08, 2015 at 07:12:31PM -0500, Andreas Dannenberg wrote:

This commit extends the use of the existing mutex to pave the way for
using direct device access inside sysfs getter/setter routines in a
way that the access during interrupts and timer routines does not
interfere with device access by the CPU or between multiple cores.

This also addresses a potential race condition that could be caused
by bq24257_irq_handler_thread() and bq24257_iilimit_autoset() accessing
the device simultaneously.

What potential race? AFAIK, we're doing all the operations through
regmap, and regmap operations are serialized. It has its own mutex for
this. Unless I got it all wrong...

So, IMHO, you don't need to protect against simultaneous device access.
It's taken care of by regmap. Chip state data protection should be enough.

laurentiu