[PATCH v2 1/3] power: supply: ltc2941: drain poll work before unregistering the supply

[hyunjungg <hj351016@gmail.com>]

From: Hyunjung Ko <hj351016@gmail.com>

ltc294x_i2c_probe() registers the poll work for devm cancellation before
devm_power_supply_register(). devres unwinds in reverse, so on unbind the
power supply is freed first and the work cancelled last. ltc294x_work()
re-queues itself and calls power_supply_changed(info->supply), so a poll
instance running in that window dereferences the freed supply.

Register the work cancellation after the power supply so devres drains it
first. Nothing queues the work before the schedule_delayed_work() that
follows, so the move is safe.

Fixes: 6d0c5de2fd84 ("power: supply: Clean-up few drivers by using managed work init")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunjung Ko <hj351016@gmail.com>
---
diff --git a/drivers/power/supply/ltc2941-battery-gauge.c b/drivers/power/supply/ltc2941-battery-gauge.c
index 6ebb555..8f8a8f6 100644
--- a/drivers/power/supply/ltc2941-battery-gauge.c
+++ b/drivers/power/supply/ltc2941-battery-gauge.c
@@ -531,11 +531,6 @@ static int ltc294x_i2c_probe(struct i2c_client *client)
 
 	psy_cfg.drv_data = info;
 
-	ret = devm_delayed_work_autocancel(&client->dev, &info->work,
-					   ltc294x_work);
-	if (ret)
-		return ret;
-
 	ret = ltc294x_reset(info, prescaler_exp);
 	if (ret < 0)
 		return dev_err_probe(&client->dev, ret,
@@ -547,6 +542,11 @@ static int ltc294x_i2c_probe(struct i2c_client *client)
 		return dev_err_probe(&client->dev, PTR_ERR(info->supply),
 			"failed to register ltc2941\n");
 
+	ret = devm_delayed_work_autocancel(&client->dev, &info->work,
+					   ltc294x_work);
+	if (ret)
+		return ret;
+
 	schedule_delayed_work(&info->work, LTC294X_WORK_DELAY * HZ);
 
 	return 0;
-- 
2.43.0

-- 
2.43.0