Patch "iio: Fix error handling in iio_trigger_attach_poll_func" has been added to the 4.6-stable tree

This is a note to let you know that I've just added the patch titled

iio: Fix error handling in iio_trigger_attach_poll_func

to the 4.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
iio-fix-error-handling-in-iio_trigger_attach_poll_func.patch
and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Crestez Dan Leonard <[email protected]>
Date: Tue, 3 May 2016 15:27:09 +0300
Subject: iio: Fix error handling in iio_trigger_attach_poll_func

From: Crestez Dan Leonard <[email protected]>

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.

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

@@ -210,22 +210,35 @@ 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,

Patches currently in stable-queue which might be from [email protected] are

queue-4.6/iio-fix-error-handling-in-iio_trigger_attach_poll_func.patch