On Fri, 22 Dec 2017 17:07:14 +0200 Eugen Hristev <[email protected]> wrote:
> When attaching a pollfunc to a trigger, if the pollfunc does not > have an associated iio_dev pointer, just use the private data > iio_dev pointer from the trigger to fill in the poll func required > iio_dev reference. > > Signed-off-by: Eugen Hristev <[email protected]> I'm yet to be convinced this is necessary rather than using a callback buffer. It's also decidedly unsafe as there is no particular reason in general to assume the private data is an iio_dev. > --- > drivers/iio/industrialio-trigger.c | 9 +++++++++ > include/linux/iio/trigger_consumer.h | 2 ++ > 2 files changed, 11 insertions(+) > > diff --git a/drivers/iio/industrialio-trigger.c > b/drivers/iio/industrialio-trigger.c > index 8565c92..ab180bd 100644 > --- a/drivers/iio/industrialio-trigger.c > +++ b/drivers/iio/industrialio-trigger.c > @@ -272,6 +272,15 @@ int iio_trigger_attach_poll_func(struct iio_trigger > *trig, > bool notinuse > = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER); > > + /* > + * If we did not get a iio_dev in the poll func, attempt to > + * obtain the trigger's owner's device struct > + */ > + if (!pf->indio_dev) > + pf->indio_dev = iio_trigger_get_drvdata(trig); That isn't always valid. Triggers don't always have a iio_dev associated with them at all. > + if (!pf->indio_dev) > + return -EINVAL; > + > /* Prevent the module from being removed whilst attached to a trigger */ > __module_get(pf->indio_dev->driver_module); > > diff --git a/include/linux/iio/trigger_consumer.h > b/include/linux/iio/trigger_consumer.h > index aeefcdb..36e2a02 100644 > --- a/include/linux/iio/trigger_consumer.h > +++ b/include/linux/iio/trigger_consumer.h > @@ -63,6 +63,8 @@ int iio_triggered_buffer_predisable(struct iio_dev > *indio_dev); > /* > * Two functions for the uncommon case when we need to attach or detach > * a specific pollfunc to and from a trigger > + * If the pollfunc has a NULL iio_dev pointer, it will be filled from the > + * trigger struct. > */ > int iio_trigger_attach_poll_func(struct iio_trigger *trig, > struct iio_poll_func *pf);
