Re: [PATCH v4 3/3] iio: accel: bmc150: use guard(mutex) for mutex handling

On Tue, Aug 18, 2026 at 04:41:35PM +0100, Gabriel Rondon wrote:
> On Mon, Aug 17, 2026 at 06:39:18PM +0300, Andy Shevchenko wrote:
> > Not directly related to this change, but even in the original code what is
> > protected here by the mutex? data->scan.channels?
> 
> Agreed it is out of scope for this cleanup, so I left the scope unchanged.
> 
> Honest answer: not much that is obvious. data->scan.channels does not need
> it, since the triggered handler is the only writer and the core serializes
> it. The accel one-shot read is already gated with -EBUSY while buffering, so
> bmc150_accel_get_axis cannot race the handler. What is left sharing
> data->mutex and still reachable during capture is the temperature read, the
> bandwidth get/set and scale set, and the event config. But since the handler
> is a single regmap_bulk_read and regmap already serializes the bus, it is not
> clear the driver mutex guards a real invariant here, and it may well be
> vestigial.

> Dropping it is a behavioral change worth its own patch and testing rather
> than something to fold into a lock-syntax cleanup.

Of course! Just made an observation.

> Happy to look into that separately.

If you have HW to test, I would like to see such a change.

-- 
With Best Regards,
Andy Shevchenko