Merge v7.1.5linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 29 insertions, 6 deletions

diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index 42cc6068bb08..e18e80e832fd 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -214,6 +214,11 @@ int occ_update_response(struct occ *occ)
 	if (rc)
 		return rc;
 
+	if (!occ->active) {
+		rc = -ENODEV;
+		goto unlock;
+	}
+
 	/* limit the maximum rate of polling the OCC */
 	if (time_after(jiffies, occ->next_update)) {
 		rc = occ_poll(occ);
@@ -222,6 +227,7 @@ int occ_update_response(struct occ *occ)
 		rc = occ->last_error;
 	}
 
+unlock:
 	mutex_unlock(&occ->lock);
 	return rc;
 }
@@ -1105,11 +1111,16 @@ static void occ_parse_poll_response(struct occ *occ)
 
 int occ_active(struct occ *occ, bool active)
 {
-	int rc = mutex_lock_interruptible(&occ->lock);
+	struct device *hwmon = NULL;
+	int rc = mutex_lock_interruptible(&occ->hwmon_lock);
 
 	if (rc)
 		return rc;
 
+	rc = mutex_lock_interruptible(&occ->lock);
+	if (rc)
+		goto unlock_hwmon;
+
 	if (active) {
 		if (occ->active) {
 			rc = -EALREADY;
@@ -1154,14 +1165,17 @@ int occ_active(struct occ *occ, bool active)
 			goto unlock;
 		}
 
-		if (occ->hwmon)
-			hwmon_device_unregister(occ->hwmon);
+		hwmon = occ->hwmon;
 		occ->active = false;
 		occ->hwmon = NULL;
 	}
 
 unlock:
 	mutex_unlock(&occ->lock);
+	if (hwmon)
+		hwmon_device_unregister(hwmon);
+unlock_hwmon:
+	mutex_unlock(&occ->hwmon_lock);
 	return rc;
 }
 
@@ -1170,6 +1184,7 @@ int occ_setup(struct occ *occ)
 	int rc;
 
 	mutex_init(&occ->lock);
+	mutex_init(&occ->hwmon_lock);
 	occ->groups[0] = &occ->group;
 
 	rc = occ_setup_sysfs(occ);
@@ -1190,15 +1205,22 @@ EXPORT_SYMBOL_GPL(occ_setup);
 
 void occ_shutdown(struct occ *occ)
 {
-	mutex_lock(&occ->lock);
+	struct device *hwmon;
 
 	occ_shutdown_sysfs(occ);
 
-	if (occ->hwmon)
-		hwmon_device_unregister(occ->hwmon);
+	mutex_lock(&occ->hwmon_lock);
+	mutex_lock(&occ->lock);
+
+	hwmon = occ->hwmon;
+	occ->active = false;
 	occ->hwmon = NULL;
 
 	mutex_unlock(&occ->lock);
+
+	if (hwmon)
+		hwmon_device_unregister(hwmon);
+	mutex_unlock(&occ->hwmon_lock);
 }
 EXPORT_SYMBOL_GPL(occ_shutdown);
 
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
index 7ac4b2febce6..82f600093c7f 100644
--- a/drivers/hwmon/occ/common.h
+++ b/drivers/hwmon/occ/common.h
@@ -101,6 +101,7 @@ struct occ {
 
 	unsigned long next_update;
 	struct mutex lock;		/* lock OCC access */
+	struct mutex hwmon_lock;		/* serialize hwmon registration/removal */
 
 	struct device *hwmon;
 	struct occ_attribute *attrs;