Trip temperatures are read using ACPI methods and stored in the memory
during zone initializtion and when the firmware sends a notification for
change. This trip temperature is returned when the thermal core calls via
callback get_trip_temp().
But it is possible that while updating the memory copy of the trips when
the firmware sends a notification for change, thermal core is reading the
trip temperature via the callback get_trip_temp(). This may return invalid
trip temperature.
To address this add a mutex to protect the invalid temperature reads in
the callback get_trip_temp() and int340x_thermal_read_trips().
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 5.0+
---
v2:
- rebased on linux-next
- Add ret variable and remove return as suugested by Rafael
.../int340x_thermal/int340x_thermal_zone.c | 18 +++++++++++++++---
.../int340x_thermal/int340x_thermal_zone.h | 1 +
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
index 228f44260b27..5fda1e67b793 100644
--- a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
+++ b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
@@ -41,7 +41,9 @@ static int int340x_thermal_get_trip_temp(struct thermal_zone_device *zone,
int trip, int *temp)
{
struct int34x_thermal_zone *d = zone->devdata;
- int i;
+ int i, ret = 0;
+
+ mutex_lock(&d->trip_mutex);
if (trip < d->aux_trip_nr)
*temp = d->aux_trips[trip];
@@ -60,10 +62,12 @@ static int int340x_thermal_get_trip_temp(struct thermal_zone_device *zone,
}
}
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_get_trip_type(struct thermal_zone_device *zone,
@@ -165,6 +169,8 @@ int int340x_thermal_read_trips(struct int34x_thermal_zone *int34x_zone)
int trip_cnt = int34x_zone->aux_trip_nr;
int i;
+ mutex_lock(&int34x_zone->trip_mutex);
+
int34x_zone->crt_trip_id = -1;
if (!int340x_thermal_get_trip_config(int34x_zone->adev->handle, "_CRT",
&int34x_zone->crt_temp))
@@ -192,6 +198,8 @@ int int340x_thermal_read_trips(struct int34x_thermal_zone *int34x_zone)
int34x_zone->act_trips[i].valid = true;
}
+ mutex_unlock(&int34x_zone->trip_mutex);
+
return trip_cnt;
}
EXPORT_SYMBOL_GPL(int340x_thermal_read_trips);
@@ -215,6 +223,8 @@ struct int34x_thermal_zone *int340x_thermal_zone_add(struct acpi_device *adev,
if (!int34x_thermal_zone)
return ERR_PTR(-ENOMEM);
+ mutex_init(&int34x_thermal_zone->trip_mutex);
+
int34x_thermal_zone->adev = adev;
int34x_thermal_zone->ops = kmemdup(&int340x_thermal_zone_ops,
@@ -277,6 +287,7 @@ struct int34x_thermal_zone *int340x_thermal_zone_add(struct acpi_device *adev,
err_trip_alloc:
kfree(int34x_thermal_zone->ops);
err_ops_alloc:
+ mutex_destroy(&int34x_thermal_zone->trip_mutex);
kfree(int34x_thermal_zone);
return ERR_PTR(ret);
}
@@ -289,6 +300,7 @@ void int340x_thermal_zone_remove(struct int34x_thermal_zone
acpi_lpat_free_conversion_table(int34x_thermal_zone->lpat_table);
kfree(int34x_thermal_zone->aux_trips);
kfree(int34x_thermal_zone->ops);
+ mutex_destroy(&int34x_thermal_zone->trip_mutex);
kfree(int34x_thermal_zone);
}
EXPORT_SYMBOL_GPL(int340x_thermal_zone_remove);
diff --git a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h
index e28ab1ba5e06..6610a9cc441b 100644
--- a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h
+++ b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.h
@@ -32,6 +32,7 @@ struct int34x_thermal_zone {
struct thermal_zone_device_ops *ops;
void *priv_data;
struct acpi_lpat_conversion_table *lpat_table;
+ struct mutex trip_mutex;
};
struct int34x_thermal_zone *int340x_thermal_zone_add(struct acpi_device *,
--
2.31.1
