Re: [PATCH] iio: pressure: rohm-bm1390: notify trigger on all error paths

[Matti Vaittinen]

On 18/05/2026 09:59, Andy Shevchenko wrote:
> On Mon, May 18, 2026 at 08:21:17AM +0300, Matti Vaittinen wrote:
> > On 17/05/2026 20:12, David Lechner wrote:
> > > On 5/17/26 11:08 AM, Stepan Ionichev wrote:
>
> ...
>
> > Maybe it would be better to do something like:
> >
> > void iio_trigger_poll_nested(struct iio_trigger *trig)
> > {
> >          int i;
> >
> >          if (!atomic_read(&trig->use_count)) {
> >                  atomic_set(&trig->use_count,
> > CONFIG_IIO_CONSUMERS_PER_TRIGGER);
>
> Just in case somebody is going to do that, avoid doing atomic_read() followed
> by atomic_set(). This is typical TOCTOU issue. This should be something like
> atomic_xchg() or atomic_add_return() or something like this in a single atomic
> operation.

Well spotted Andy. This is existing code, so perhaps this should be 
fixed if the logic won't be altered after this discussion.

Yours,
	-- Matti

--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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