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Message-Id: <1543358591-25189-1-git-send-email-thara.gopinath@linaro.org>
Date: Tue, 27 Nov 2018 17:43:11 -0500
From: Thara Gopinath <thara.gopinath@...aro.org>
To: rui.zhang@...el.com, edubezval@...il.com, daniel.lezcano@...aro.org
Cc: linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH V2] thermal: Fix locking in cooling device sysfs update cur_state
Sysfs interface to update cooling device cur_state does not
currently holding cooling device lock sometimes leading to
stale values in cur_state if getting updated simultanelously
from user space and thermal framework. Adding the proper locking
code fixes this issue.
Signed-off-by: Thara Gopinath <thara.gopinath@...aro.org>
---
V1->V2: Rearranged the code as per Daniel's review comment
drivers/thermal/thermal_sysfs.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index 2241cea..aa99edb 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -712,11 +712,14 @@ cur_state_store(struct device *dev, struct device_attribute *attr,
if ((long)state < 0)
return -EINVAL;
+ mutex_lock(&cdev->lock);
+
result = cdev->ops->set_cur_state(cdev, state);
- if (result)
- return result;
- thermal_cooling_device_stats_update(cdev, state);
- return count;
+ if (!result)
+ thermal_cooling_device_stats_update(cdev, state);
+
+ mutex_unlock(&cdev->lock);
+ return result ? result : count;
}
static struct device_attribute
--
2.1.4
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