linux-kernel - [PATCH v4 1/2] power_supply: Register cooling device outside of probe

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Date:   Wed, 22 Dec 2021 14:11:28 +0530
From:   Manaf Meethalavalappu Pallikunhi <quic_manafm@...cinc.com>
To:     Sebastian Reichel <sre@...nel.org>
CC:     <linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        David Collins <quic_collinsd@...cinc.com>,
        Subbaraman Narayanamurthy <quic_subbaram@...cinc.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        "thara . gopinath @ linaro . org" <thara.gopinath@...aro.org>,
        "Manaf Meethalavalappu Pallikunhi" <quic_manafm@...cinc.com>
Subject: [PATCH v4 1/2] power_supply: Register cooling device outside of probe

Registering the cooling device from the probe can result in the
execution of get_property() function before it gets initialized.

To avoid this, register the cooling device from a workqueue
instead of registering in the probe.

Signed-off-by: Manaf Meethalavalappu Pallikunhi <quic_manafm@...cinc.com>
---
 drivers/power/supply/power_supply_core.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 668369b..ef6f290 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -132,6 +132,7 @@ void power_supply_changed(struct power_supply *psy)
 }
 EXPORT_SYMBOL_GPL(power_supply_changed);
 
+static int psy_register_cooler(struct power_supply *psy);
 /*
  * Notify that power supply was registered after parent finished the probing.
  *
@@ -139,6 +140,8 @@ EXPORT_SYMBOL_GPL(power_supply_changed);
  * calling power_supply_changed() directly from power_supply_register()
  * would lead to execution of get_property() function provided by the driver
  * too early - before the probe ends.
+ * Also, registering cooling device from the probe will execute the
+ * get_property() function. So register the cooling device after the probe.
  *
  * Avoid that by waiting on parent's mutex.
  */
@@ -156,6 +159,7 @@ static void power_supply_deferred_register_work(struct work_struct *work)
 	}
 
 	power_supply_changed(psy);
+	psy_register_cooler(psy);
 
 	if (psy->dev.parent)
 		mutex_unlock(&psy->dev.parent->mutex);
@@ -1238,10 +1242,6 @@ __power_supply_register(struct device *parent,
 	if (rc)
 		goto register_thermal_failed;
 
-	rc = psy_register_cooler(psy);
-	if (rc)
-		goto register_cooler_failed;
-
 	rc = power_supply_create_triggers(psy);
 	if (rc)
 		goto create_triggers_failed;
@@ -1271,8 +1271,6 @@ __power_supply_register(struct device *parent,
 add_hwmon_sysfs_failed:
 	power_supply_remove_triggers(psy);
 create_triggers_failed:
-	psy_unregister_cooler(psy);
-register_cooler_failed:
 	psy_unregister_thermal(psy);
 register_thermal_failed:
 	device_del(dev);