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>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c
index 8d0fe431dbdd..84419af16f77 100644
--- 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;