[PATCH] power: supply: bq27xxx: Ensure poll work is cancelled on remove

[Fan Wu]

The di->work poll work is queued from the poll callback itself and from
bq27xxx_external_power_changed(). The cancel_delayed_work_sync() in
bq27xxx_battery_teardown() runs while the power_supply is still
registered, so external_power_changed() can re-arm the work after the
cancel, and it runs after the driver data has been freed.

Register a devm_delayed_work_autocancel() before
devm_power_supply_register(), so on unwind the power_supply is
unregistered first, after which no new external_power_changed()
callback can be dispatched, and the poll work is cancelled only then.
Drop the now-redundant cancel from bq27xxx_battery_teardown().

This issue was found by an in-house static analysis tool.

Fixes: 740b755a3b34 ("bq27x00: Poll battery state")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: Codex:gpt-5.6
Co-developed-by: Song Li <songl@xxxxxxxxxx>
Signed-off-by: Song Li <songl@xxxxxxxxxx>
Signed-off-by: Fan Wu <fanwu01@xxxxxxxxxx>
---
 drivers/power/supply/bq27xxx_battery.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c
index 45f0e39b8c2d..f175c5a99188 100644
--- a/drivers/power/supply/bq27xxx_battery.c
+++ b/drivers/power/supply/bq27xxx_battery.c
@@ -43,6 +43,7 @@
  */
 
 #include <linux/device.h>
+#include <linux/devm-helpers.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/param.h>
@@ -2234,7 +2235,6 @@ int bq27xxx_battery_setup(struct bq27xxx_device_info *di)
 	};
 	int ret;
 
-	INIT_DELAYED_WORK(&di->work, bq27xxx_battery_poll);
 	ret = devm_mutex_init(di->dev, &di->lock);
 	if (ret)
 		return ret;
@@ -2255,6 +2255,12 @@ int bq27xxx_battery_setup(struct bq27xxx_device_info *di)
 	psy_desc->get_property = bq27xxx_battery_get_property;
 	psy_desc->external_power_changed = bq27xxx_external_power_changed;
 
+	/* Cancel the poll work after the power_supply is unregistered. */
+	ret = devm_delayed_work_autocancel(di->dev, &di->work,
+					   bq27xxx_battery_poll);
+	if (ret)
+		return ret;
+
 	di->bat = devm_power_supply_register(di->dev, psy_desc, &psy_cfg);
 	if (IS_ERR(di->bat))
 		return dev_err_probe(di->dev, PTR_ERR(di->bat),
@@ -2281,8 +2287,6 @@ void bq27xxx_battery_teardown(struct bq27xxx_device_info *di)
 	mutex_lock(&di->lock);
 	di->removed = true;
 	mutex_unlock(&di->lock);
-
-	cancel_delayed_work_sync(&di->work);
 }
 EXPORT_SYMBOL_GPL(bq27xxx_battery_teardown);