[PATCH 5.15.y] power: supply: bq27xxx: Ensure poll work is cancelled on remove

[Sasha Levin <sashal@kernel.org>]

From: Fan Wu <fanwu01@zju.edu.cn>

[ Upstream commit db560f4b1c5253853f978385db066220e0c218dc ]

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@vger.kernel.org
Assisted-by: Codex:gpt-5.6
Co-developed-by: Song Li <songl@zju.edu.cn>
Signed-off-by: Song Li <songl@zju.edu.cn>
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
Link: https://patch.msgid.link/20260903081312.225535-1-fanwu01@zju.edu.cn
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
[ sashal: added devm_mutex_init() with error handling to replace manual mutex setup and teardown ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/power/supply/bq27xxx_battery.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c
index d4c694045209f..6486a039951e5 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>
@@ -2141,9 +2142,11 @@ int bq27xxx_battery_setup(struct bq27xxx_device_info *di)
 		.of_node = di->dev->of_node,
 		.drv_data = di,
 	};
+	int ret;
 
-	INIT_DELAYED_WORK(&di->work, bq27xxx_battery_poll);
-	mutex_init(&di->lock);
+	ret = devm_mutex_init(di->dev, &di->lock);
+	if (ret)
+		return ret;
 
 	di->regs       = bq27xxx_chip_data[di->chip].regs;
 	di->unseal_key = bq27xxx_chip_data[di->chip].unseal_key;
@@ -2161,6 +2164,12 @@ 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 = power_supply_register_no_ws(di->dev, psy_desc, &psy_cfg);
 	if (IS_ERR(di->bat))
 		return dev_err_probe(di->dev, PTR_ERR(di->bat),
@@ -2188,10 +2197,7 @@ void bq27xxx_battery_teardown(struct bq27xxx_device_info *di)
 	di->removed = true;
 	mutex_unlock(&di->lock);
 
-	cancel_delayed_work_sync(&di->work);
-
 	power_supply_unregister(di->bat);
-	mutex_destroy(&di->lock);
 }
 EXPORT_SYMBOL_GPL(bq27xxx_battery_teardown);
 
-- 
2.53.0