[PATCH 3.14 38/53] iio: Fix error handling in iio_trigger_attach_poll_func

Greg Kroah-Hartman
2016-07-25T20:56:07Z

From: Crestez Dan Leonard <leonard.crestez@intel.com>

commit 99543823357966ac938d9a310947e731b67338e6 upstream.

When attaching a pollfunc iio_trigger_attach_poll_func will allocate a
virtual irq and call the driver's set_trigger_state function. Fix error
handling to undo previous steps if any fails.

In particular this fixes handling errors from a driver's
set_trigger_state function. When using triggered buffers a failure to
enable the trigger used to make the buffer unusable.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iio/industrialio-trigger.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)

--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -205,22 +205,35 @@ static int iio_trigger_attach_poll_func(

/* Prevent the module from being removed whilst attached to a trigger */
__module_get(pf->indio_dev->info->driver_module);
+
+ /* Get irq number */
pf->irq = iio_trigger_get_irq(trig);
+ if (pf->irq < 0)
+ goto out_put_module;
+
+ /* Request irq */
ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
pf->type, pf->name,
pf);
- if (ret < 0) {
- module_put(pf->indio_dev->info->driver_module);
- return ret;
- }
+ if (ret < 0)
+ goto out_put_irq;

+ /* Enable trigger in driver */
if (trig->ops && trig->ops->set_trigger_state && notinuse) {
ret = trig->ops->set_trigger_state(trig, true);
if (ret < 0)
- module_put(pf->indio_dev->info->driver_module);
+ goto out_free_irq;
}

return ret;
+
+out_free_irq:
+ free_irq(pf->irq, pf);
+out_put_irq:
+ iio_trigger_put_irq(trig, pf->irq);
+out_put_module:
+ module_put(pf->indio_dev->info->driver_module);
+ return ret;
}

static int iio_trigger_detach_poll_func(struct iio_trigger *trig,