PowerCap: Fix mode for energy counter

As per the documentation of powercap sysfs, energy_uj field is read only,
if it can't be reset. Currently it always allows write but will fail,
if there is no reset callback.
Changing mode field, to read only if there is no reset callback.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reported-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c
index 8d0fe431dbdd54ef0c175c06dbbc4b5d76f6d9cd..84419af16f777095687eddb59d74c7ca6762e3bb 100644 (file)
--- a/drivers/powercap/powercap_sys.c
+++ b/drivers/powercap/powercap_sys.c
@@ -377,9 +377,14 @@ static void create_power_zone_common_attributes(
        if (power_zone->ops->get_max_energy_range_uj)
                power_zone->zone_dev_attrs[count++] =
                                        &dev_attr_max_energy_range_uj.attr;
-       if (power_zone->ops->get_energy_uj)
+       if (power_zone->ops->get_energy_uj) {
+               if (power_zone->ops->reset_energy_uj)
+                       dev_attr_energy_uj.attr.mode = S_IWUSR | S_IRUGO;
+               else
+                       dev_attr_energy_uj.attr.mode = S_IRUGO;
                power_zone->zone_dev_attrs[count++] =
                                        &dev_attr_energy_uj.attr;
+       }
        if (power_zone->ops->get_power_uw)
                power_zone->zone_dev_attrs[count++] =
                                        &dev_attr_power_uw.attr;