[PATCH 1/4] thermal/drivers/qcom: fix set_trip_temp() deadlock

From: Johan Hovold <johan+linaro@kernel.org>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>
Cc: Amit Kucheria <amitk@kernel.org>,
	Thara Gopinath <thara.gopinath@gmail.com>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	Zhang Rui <rui.zhang@intel.com>,
	Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	linux-pm@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-tegra@vger.kernel.org,
	Johan Hovold <johan+linaro@kernel.org>
Subject: [PATCH 1/4] thermal/drivers/qcom: fix set_trip_temp() deadlock
Date: Wed, 14 Dec 2022 14:16:14 +0100	[thread overview]
Message-ID: <20221214131617.2447-2-johan+linaro@kernel.org> (raw)
In-Reply-To: <20221214131617.2447-1-johan+linaro@kernel.org>

The set_trip_temp() callback is used when changing the trip temperature
through sysfs. As it is called with the thermal-zone-device lock held
it must not use thermal_zone_get_trip() directly or it will deadlock.

Fixes: 78c3e2429be8 ("thermal/drivers/qcom: Use generic thermal_zone_get_trip() function")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/thermal/qcom/qcom-spmi-temp-alarm.c | 2 +-
 drivers/thermal/thermal_core.c              | 1 +
 include/linux/thermal.h                     | 2 ++
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
index 58055a7abaf6..bfaec74f13b2 100644
--- a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
+++ b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
@@ -270,7 +270,7 @@ static int qpnp_tm_set_trip_temp(struct thermal_zone_device *tz, int trip_id, in
 	struct thermal_trip trip;
 	int ret;
 
-	ret = thermal_zone_get_trip(chip->tz_dev, trip_id, &trip);
+	ret = __thermal_zone_get_trip(chip->tz_dev, trip_id, &trip);
 	if (ret)
 		return ret;
 
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index c24c9efcd175..d9a3d9566d73 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -1214,6 +1214,7 @@ int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 
 	return tz->ops->get_trip_type(tz, trip_id, &trip->type);
 }
+EXPORT_SYMBOL_GPL(__thermal_zone_get_trip);
 
 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 			  struct thermal_trip *trip)
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index e2797f314d99..30353e4b1424 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -334,6 +334,8 @@ static inline void devm_thermal_of_zone_unregister(struct device *dev,
 }
 #endif
 
+int __thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
+			    struct thermal_trip *trip);
 int thermal_zone_get_trip(struct thermal_zone_device *tz, int trip_id,
 			  struct thermal_trip *trip);
 
-- 
2.37.4

