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authorRafael J. Wysocki <rjw@sisk.pl>2010-10-23 19:35:15 +0200
committerLen Brown <len.brown@intel.com>2010-10-23 20:05:03 +0200
commita1b4bd694a803eba49d637de32bb249638ceadb4 (patch)
tree30b3b4efbf394b8cd500b694c80485561a6827ab /drivers/acpi/battery.c
parentLinux 2.6.36 (diff)
downloadlinux-a1b4bd694a803eba49d637de32bb249638ceadb4.tar.xz
linux-a1b4bd694a803eba49d637de32bb249638ceadb4.zip
ACPI / Battery: Return -ENODEV for unknown values in get_property()
The function acpi_battery_get_property() is called by the power supply framework's function power_supply_show_property() implementing the sysfs interface for power supply devices as the ACPI battery driver's ->get_property() callback. Thus it is supposed to return error code if the value of the given property is unknown. Unfortunately, however, it returns 0 in those cases and puts a wrong (negative) value into the intval field of the union power_supply_propval object provided by power_supply_show_property(). In consequence, wrong negative values are read by user space from the battery's sysfs files. Fix this by making acpi_battery_get_property() return -ENODEV for properties with unknown values (-ENODEV is returned, because power_supply_uevent() returns with error for any other error code returned by power_supply_show_property()). Reported-and-tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/battery.c')
-rw-r--r--drivers/acpi/battery.c35
1 files changed, 27 insertions, 8 deletions
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 98417201e9ce..ac74a7ddaaa4 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -186,6 +186,7 @@ static int acpi_battery_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
+ int ret = 0;
struct acpi_battery *battery = to_acpi_battery(psy);
if (acpi_battery_present(battery)) {
@@ -214,26 +215,44 @@ static int acpi_battery_get_property(struct power_supply *psy,
val->intval = battery->cycle_count;
break;
case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
- val->intval = battery->design_voltage * 1000;
+ if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
+ ret = -ENODEV;
+ else
+ val->intval = battery->design_voltage * 1000;
break;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
- val->intval = battery->voltage_now * 1000;
+ if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
+ ret = -ENODEV;
+ else
+ val->intval = battery->voltage_now * 1000;
break;
case POWER_SUPPLY_PROP_CURRENT_NOW:
case POWER_SUPPLY_PROP_POWER_NOW:
- val->intval = battery->rate_now * 1000;
+ if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
+ ret = -ENODEV;
+ else
+ val->intval = battery->rate_now * 1000;
break;
case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
- val->intval = battery->design_capacity * 1000;
+ if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+ ret = -ENODEV;
+ else
+ val->intval = battery->design_capacity * 1000;
break;
case POWER_SUPPLY_PROP_CHARGE_FULL:
case POWER_SUPPLY_PROP_ENERGY_FULL:
- val->intval = battery->full_charge_capacity * 1000;
+ if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+ ret = -ENODEV;
+ else
+ val->intval = battery->full_charge_capacity * 1000;
break;
case POWER_SUPPLY_PROP_CHARGE_NOW:
case POWER_SUPPLY_PROP_ENERGY_NOW:
- val->intval = battery->capacity_now * 1000;
+ if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
+ ret = -ENODEV;
+ else
+ val->intval = battery->capacity_now * 1000;
break;
case POWER_SUPPLY_PROP_MODEL_NAME:
val->strval = battery->model_number;
@@ -245,9 +264,9 @@ static int acpi_battery_get_property(struct power_supply *psy,
val->strval = battery->serial_number;
break;
default:
- return -EINVAL;
+ ret = -EINVAL;
}
- return 0;
+ return ret;
}
static enum power_supply_property charge_battery_props[] = {