Re: [PATCH v2 07/13] power: bq24257: Extend scope of mutex protection

Laurentiu Palcu
2015-09-10T13:43:10Z

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