[PATCH AUTOSEL 6.18-6.12] hwmon: (raspberrypi) Fix delayed-work teardown race

[Sasha Levin]

From: Shubham Chakraborty <chakrabortyshubham66 at gmail.com>

[ Upstream commit eb0d491e2787aa359f0d930151ff6e5e5df70fb9 ]

The delayed polling work rearms itself from the work function, so use
explicit delayed-work setup and cleanup instead of
devm_delayed_work_autocancel().

Initialize the delayed work with INIT_DELAYED_WORK() and register a
devres cleanup action that calls disable_delayed_work_sync() during
teardown.

This addresses the concern raised during review about the polling work
being able to requeue itself while the driver is being removed.

Signed-off-by: Shubham Chakraborty <chakrabortyshubham66 at gmail.com>
Link: https://lore.kernel.org/r/20260517080445.103962-4-chakrabortyshubham66@gmail.com
Signed-off-by: Guenter Roeck <linux at roeck-us.net>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---

LLM Generated explanations, may be completely bogus:

Those background searches finished and match the earlier analysis:

- On **6.18.44 (HEAD)**, `git log --grep` does not find this fix — only
  unrelated teardown commits show up.
- On **master**, the fix is **`eb0d491e2787a`** (`hwmon: (raspberrypi)
  Fix delayed-work teardown race`), merged via the `hwmon-for-v7.2` tag.
- It is present on **next** branches (`all-next`, `arch-next`, etc.) but
  **not** on the checked-out **6.18.y** stable tree.

That confirms the patch still needs to be backported to 6.18.44, and the
**YES** recommendation stands.

 drivers/hwmon/raspberrypi-hwmon.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/raspberrypi-hwmon.c b/drivers/hwmon/raspberrypi-hwmon.c
index a2938881ccd2f..b0f0f50986b9a 100644
--- a/drivers/hwmon/raspberrypi-hwmon.c
+++ b/drivers/hwmon/raspberrypi-hwmon.c
@@ -7,7 +7,6 @@
  * Copyright (C) 2018 Stefan Wahren <stefan.wahren at i2se.com>
  */
 #include <linux/device.h>
-#include <linux/devm-helpers.h>
 #include <linux/err.h>
 #include <linux/hwmon.h>
 #include <linux/module.h>
@@ -72,6 +71,13 @@ static void get_values_poll(struct work_struct *work)
 	schedule_delayed_work(&data->get_values_poll_work, 2 * HZ);
 }
 
+static void rpi_hwmon_cancel_poll_work(void *res)
+{
+	struct rpi_hwmon_data *data = res;
+
+	disable_delayed_work_sync(&data->get_values_poll_work);
+}
+
 static int rpi_read(struct device *dev, enum hwmon_sensor_types type,
 		    u32 attr, int channel, long *val)
 {
@@ -117,8 +123,8 @@ static int rpi_hwmon_probe(struct platform_device *pdev)
 	if (IS_ERR(data->hwmon_dev))
 		return PTR_ERR(data->hwmon_dev);
 
-	ret = devm_delayed_work_autocancel(dev, &data->get_values_poll_work,
-					   get_values_poll);
+	INIT_DELAYED_WORK(&data->get_values_poll_work, get_values_poll);
+	ret = devm_add_action_or_reset(dev, rpi_hwmon_cancel_poll_work, data);
 	if (ret)
 		return ret;
 	platform_set_drvdata(pdev, data);
-- 
2.53.0