test_power: Fix a bug in setting module parameter values

When the kernel loads a module, module params are processed prior to
calling module_init. As a result, setting module param value should not
have side effects, at least as long as the module has not been
initialized.

Signed-off-by: Andrey Gelman <andreyg@compulab.co.il>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

1 files changed, 21 insertions, 10 deletions

diff --git a/drivers/power/test_power.c b/drivers/power/test_power.c
index b99a452a4fda..0152f35dca5c 100644
--- a/drivers/power/test_power.c
+++ b/drivers/power/test_power.c
@@ -30,6 +30,8 @@ static int battery_technology		= POWER_SUPPLY_TECHNOLOGY_LION;
 static int battery_capacity             = 50;
 static int battery_voltage              = 3300;
 
+static bool module_initialized;
+
 static int test_power_get_ac_property(struct power_supply *psy,
                                       enum power_supply_property psp,
                                       union power_supply_propval *val)
@@ -185,6 +187,7 @@ static int __init test_power_init(void)
                 }
         }
 
+        module_initialized = true;
         return 0;
 failed:
         while (--i >= 0)
@@ -209,6 +212,8 @@ static void __exit test_power_exit(void)
 
         for (i = 0; i < ARRAY_SIZE(test_power_supplies); i++)
                 power_supply_unregister(&test_power_supplies[i]);
+
+        module_initialized = false;
 }
 module_exit(test_power_exit);
 
@@ -221,8 +226,8 @@ struct battery_property_map {
 };
 
 static struct battery_property_map map_ac_online[] = {
-        { 0,  "on"  },
-        { 1,  "off" },
+        { 0,  "off"  },
+        { 1,  "on" },
         { -1, NULL  },
 };
 
@@ -295,10 +300,16 @@ static const char *map_get_key(struct battery_property_map *map, int value,
         return def_key;
 }
 
+static inline void signal_power_supply_changed(struct power_supply *psy)
+{
+        if (module_initialized)
+                power_supply_changed(psy);
+}
+
 static int param_set_ac_online(const char *key, const struct kernel_param *kp)
 {
         ac_online = map_get_value(map_ac_online, key, ac_online);
-        power_supply_changed(&test_power_supplies[0]);
+        signal_power_supply_changed(&test_power_supplies[0]);
         return 0;
 }
 
@@ -311,7 +322,7 @@ static int param_get_ac_online(char *buffer, const struct kernel_param *kp)
 static int param_set_usb_online(const char *key, const struct kernel_param *kp)
 {
         usb_online = map_get_value(map_ac_online, key, usb_online);
-        power_supply_changed(&test_power_supplies[2]);
+        signal_power_supply_changed(&test_power_supplies[2]);
         return 0;
 }
 
@@ -325,7 +336,7 @@ static int param_set_battery_status(const char *key,
                                         const struct kernel_param *kp)
 {
         battery_status = map_get_value(map_status, key, battery_status);
-        power_supply_changed(&test_power_supplies[1]);
+        signal_power_supply_changed(&test_power_supplies[1]);
         return 0;
 }
 
@@ -339,7 +350,7 @@ static int param_set_battery_health(const char *key,
                                         const struct kernel_param *kp)
 {
         battery_health = map_get_value(map_health, key, battery_health);
-        power_supply_changed(&test_power_supplies[1]);
+        signal_power_supply_changed(&test_power_supplies[1]);
         return 0;
 }
 
@@ -353,7 +364,7 @@ static int param_set_battery_present(const char *key,
                                         const struct kernel_param *kp)
 {
         battery_present = map_get_value(map_present, key, battery_present);
-        power_supply_changed(&test_power_supplies[0]);
+        signal_power_supply_changed(&test_power_supplies[0]);
         return 0;
 }
 
@@ -369,7 +380,7 @@ static int param_set_battery_technology(const char *key,
 {
         battery_technology = map_get_value(map_technology, key,
                                                 battery_technology);
-        power_supply_changed(&test_power_supplies[1]);
+        signal_power_supply_changed(&test_power_supplies[1]);
         return 0;
 }
 
@@ -390,7 +401,7 @@ static int param_set_battery_capacity(const char *key,
                 return -EINVAL;
 
         battery_capacity = tmp;
-        power_supply_changed(&test_power_supplies[1]);
+        signal_power_supply_changed(&test_power_supplies[1]);
         return 0;
 }
 
@@ -405,7 +416,7 @@ static int param_set_battery_voltage(const char *key,
                 return -EINVAL;
 
         battery_voltage = tmp;
-        power_supply_changed(&test_power_supplies[1]);
+        signal_power_supply_changed(&test_power_supplies[1]);
         return 0;
 }