Skip to contentSkip to conversation

FAILED: patch "[PATCH] iio:accel:mxc4005: rearrange iio trigger get and register" failed to apply to 4.14-stable tree

PATCH [email protected] 1 participant 1 message Jun 27, 2022

Subsystems (2)
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9354c224c9b4f55847a0de3e968cba2ebf15af3b Mon Sep 17 00:00:00 2001
From: Dmitry Rokosov <[email protected]>
Date: Tue, 24 May 2022 18:14:43 +0000
Subject: [PATCH] iio:accel:mxc4005: rearrange iio trigger get and register

IIO trigger interface function iio_trigger_get() should be called after iio_trigger_register() (or its devm analogue) strictly, because of iio_trigger_get() acquires module refcnt based on the trigger->owner pointer, which is initialized inside iio_trigger_register() to THIS_MODULE.
If this call order is wrong, the next iio_trigger_put() (from sysfs callback or "delete module" path) will dereference "default" module refcnt, which is incorrect behaviour.

Fixes 47196620c82f ("iio: mxc4005: add data ready trigger for mxc4005")
drivers/iio/accel/mxc4005.c +2 -2
index b3afbf064915..df600d2917c0 100644
@@ -456,8 +456,6 @@ static int mxc4005_probe(struct i2c_client *client,
 
 		data->dready_trig->ops = &mxc4005_trigger_ops;
 		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
-		indio_dev->trig = data->dready_trig;
-		iio_trigger_get(indio_dev->trig);
 		ret = devm_iio_trigger_register(&client->dev,
 						data->dready_trig);
 		if (ret) {
@@ -465,6 +463,8 @@ static int mxc4005_probe(struct i2c_client *client,
 				"failed to register trigger\n");
 			return ret;
 		}
+
+		indio_dev->trig = iio_trigger_get(data->dready_trig);
 	}
 
 	return devm_iio_device_register(&client->dev, indio_dev);