Re: [PATCH] ACPI / Battery: Return -ENODATA for unknown values inget_property()

From: Pavel Machek
Date: Mon Oct 25 2010 - 09:17:58 EST


Hi!

> That's why I suggested to use -ENODATA. :-)
>
> Still, if user space has problems with failing reads from the sysfs attributes,
> it may be better to simply put -1 in there. Patch is appended, please test.

I'd say that reporting -1 for unknown is ugly. You can have -1A
current easily (charging at 1A), and I've seen machines reporting <0
current -- when charging. Logical and well-defined.

Pavel


> case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
> - val->intval = battery->design_voltage * 1000;
> + if (battery->design_voltage != ACPI_BATTERY_VALUE_UNKNOWN)
> + 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)
> + 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)
> + 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)
> + 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)
> + 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)
> + val->intval = battery->capacity_now * 1000;
> break;
> case POWER_SUPPLY_PROP_MODEL_NAME:
> val->strval = battery->model_number;
> --
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