From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Linux PM <linux-pm@vger.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>
Subject: [PATCH v1] thermal: intel: int340x: Add locking to int340x_thermal_get_trip_type()
Date:   Wed, 25 Jan 2023 13:17:42 +0100
Message-ID: <2688799.mvXUDI8C0e@kreacher>
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

In order to prevent int340x_thermal_get_trip_type() from possibly
racing with int340x_thermal_read_trips() invoked by int3403_notify()
add locking to it in analogy with int340x_thermal_get_trip_temp().

Fixes: 6757a7abe47b ("thermal: intel: int340x: Protect trip temperature from concurrent updates")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

On top of the linux-next branch in linux-pm.git from today.

---
 drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Index: linux-pm/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
===================================================================
--- linux-pm.orig/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
+++ linux-pm/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
@@ -75,7 +75,9 @@ static int int340x_thermal_get_trip_type
 					 enum thermal_trip_type *type)
 {
 	struct int34x_thermal_zone *d = zone->devdata;
-	int i;
+	int i, ret = 0;
+
+	mutex_lock(&d->trip_mutex);
 
 	if (trip < d->aux_trip_nr)
 		*type = THERMAL_TRIP_PASSIVE;
@@ -94,10 +96,12 @@ static int int340x_thermal_get_trip_type
 			}
 		}
 		if (i == INT340X_THERMAL_MAX_ACT_TRIP_COUNT)
-			return -EINVAL;
+			ret = -EINVAL;
 	}
 
-	return 0;
+	mutex_unlock(&d->trip_mutex);
+
+	return ret;
 }
 
 static int int340x_thermal_set_trip_temp(struct thermal_zone_device *zone,