Skip to contentSkip to conversation

FAILED: patch "[PATCH] iio:humidity:hts221: rearrange iio trigger get and register" failed to apply to 5.10-stable tree

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

Subsystems (3)
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 5.10-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 10b9c2c33ac706face458feab8965f11743c98c0 Mon Sep 17 00:00:00 2001
From: Dmitry Rokosov <[email protected]>
Date: Tue, 24 May 2022 18:14:46 +0000
Subject: [PATCH] iio:humidity:hts221: 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 e4a70e3e7d84 ("iio: humidity: add support to hts221 rh/temp combo device")
drivers/iio/humidity/hts221_buffer.c +4 -1
index f29692b9d2db..66b32413cf5e 100644
@@ -135,9 +135,12 @@ int hts221_allocate_trigger(struct iio_dev *iio_dev)
 
 	iio_trigger_set_drvdata(hw->trig, iio_dev);
 	hw->trig->ops = &hts221_trigger_ops;
+
+	err = devm_iio_trigger_register(hw->dev, hw->trig);
+
 	iio_dev->trig = iio_trigger_get(hw->trig);
 
-	return devm_iio_trigger_register(hw->dev, hw->trig);
+	return err;
 }
 
 static int hts221_buffer_preenable(struct iio_dev *iio_dev)