thermal: intel: int340x: Protect trip temperature from concurrent updates
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().
Fixes: 5fbf7f27fa3d ("Thermal/int340x: Add common thermal zone handler")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 5.0+ <stable@vger.kernel.org> # 5.0+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
index 62c0aa5..852f6c5 100644
--- a/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
+++ b/drivers/thermal/intel/int340x_thermal/int340x_thermal_zone.c
@@ -44,11 +44,13 @@
int trip, int *temp)
{
struct int34x_thermal_zone *d = zone->devdata;
- int i;
+ int i, ret = 0;
if (d->override_ops && d->override_ops->get_trip_temp)
return d->override_ops->get_trip_temp(zone, trip, temp);
+ mutex_lock(&d->trip_mutex);
+
if (trip < d->aux_trip_nr)
*temp = d->aux_trips[trip];
else if (trip == d->crt_trip_id)
@@ -66,10 +68,12 @@
}
}
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,
@@ -180,6 +184,8 @@
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))
@@ -207,6 +213,8 @@
int34x_zone->act_trips[i].valid = true;
}
+ mutex_unlock(&int34x_zone->trip_mutex);
+
return trip_cnt;
}
EXPORT_SYMBOL_GPL(int340x_thermal_read_trips);
@@ -230,6 +238,8 @@
if (!int34x_thermal_zone)
return ERR_PTR(-ENOMEM);
+ mutex_init(&int34x_thermal_zone->trip_mutex);
+
int34x_thermal_zone->adev = adev;
int34x_thermal_zone->override_ops = override_ops;
@@ -281,6 +291,7 @@
acpi_lpat_free_conversion_table(int34x_thermal_zone->lpat_table);
kfree(int34x_thermal_zone->aux_trips);
err_trip_alloc:
+ mutex_destroy(&int34x_thermal_zone->trip_mutex);
kfree(int34x_thermal_zone);
return ERR_PTR(ret);
}
@@ -292,6 +303,7 @@
thermal_zone_device_unregister(int34x_thermal_zone->zone);
acpi_lpat_free_conversion_table(int34x_thermal_zone->lpat_table);
kfree(int34x_thermal_zone->aux_trips);
+ 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 3b4971d..8f9872a 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 thermal_zone_device_ops *override_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 *,
