0% battery reported because _AVG postfix is ignored in battery uevent

[crozone]

Issue:

The battery_info module reports 0% for some battery power supply drivers. This is because the _AVG postfix is not handled.

Detail:

According to the specification laid out in https://www.kernel.org/doc/Documentation/power/power_supply_class.txt, battery uevent can report values with two potential postfixes:

Postfixes:
_AVG - hardware averaged value, use it if your hardware is really able to
report averaged values.
_NOW - momentary/instantaneous values.

Currently only the _NOW postfix is handled, so drivers that report hardware averaged values and not momentary/instantaneous values will not work.

This breaks when used with the pmu_battery module on Apple iBooks. For example, the iBook Clamshell with pmu_battery exports this uevent at /sys/class/power_supply/PMU_battery_0/uevent:

POWER_SUPPLY_NAME=PMU_battery_0
POWER_SUPPLY_TYPE=Unknown
POWER_SUPPLY_STATUS=Charging
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_MODEL_NAME=Smart
POWER_SUPPLY_ENERGY_AVG=391000
POWER_SUPPLY_ENERGY_FULL=3965000
POWER_SUPPLY_CURRENT_AVG=1204000
POWER_SUPPLY_VOLTAGE_AVG=14432000
POWER_SUPPLY_TIME_TO_EMPTY_AVG=10686

The following code should probably be modified to handle the _AVG postfix, and prioritize the _AVG postfix version over the _NOW postfix version:

i3status/src/print_battery_info.c

Lines 155 to 200 in 30a32cc

	for (walk = buf, last = buf; (walk - buf) < 1024; walk++) {
	if (*walk == '\n') {
	last = walk + 1;
	continue;
	}
	if (*walk != '=')
	continue;
	if (BEGINS_WITH(last, "POWER_SUPPLY_ENERGY_NOW=")) {
	watt_as_unit = true;
	batt_info->remaining = atoi(walk + 1);
	batt_info->percentage_remaining = -1;
	} else if (BEGINS_WITH(last, "POWER_SUPPLY_CHARGE_NOW=")) {
	watt_as_unit = false;
	batt_info->remaining = atoi(walk + 1);
	batt_info->percentage_remaining = -1;
	} else if (BEGINS_WITH(last, "POWER_SUPPLY_CAPACITY=") && batt_info->remaining == -1) {
	batt_info->percentage_remaining = atoi(walk + 1);
	} else if (BEGINS_WITH(last, "POWER_SUPPLY_CURRENT_NOW="))
	batt_info->present_rate = abs(atoi(walk + 1));
	else if (BEGINS_WITH(last, "POWER_SUPPLY_VOLTAGE_NOW="))
	voltage = abs(atoi(walk + 1));
	else if (BEGINS_WITH(last, "POWER_SUPPLY_TIME_TO_EMPTY_NOW="))
	batt_info->seconds_remaining = abs(atoi(walk + 1)) * 60;
	/* on some systems POWER_SUPPLY_POWER_NOW does not exist, but actually
	* it is the same as POWER_SUPPLY_CURRENT_NOW but with μWh as
	* unit instead of μAh. We will calculate it as we need it
	* later. */
	else if (BEGINS_WITH(last, "POWER_SUPPLY_POWER_NOW="))
	batt_info->present_rate = abs(atoi(walk + 1));
	else if (BEGINS_WITH(last, "POWER_SUPPLY_STATUS=Charging"))
	batt_info->status = CS_CHARGING;
	else if (BEGINS_WITH(last, "POWER_SUPPLY_STATUS=Full"))
	batt_info->status = CS_FULL;
	else if (BEGINS_WITH(last, "POWER_SUPPLY_STATUS=Discharging") || BEGINS_WITH(last, "POWER_SUPPLY_STATUS=Not charging"))
	batt_info->status = CS_DISCHARGING;
	else if (BEGINS_WITH(last, "POWER_SUPPLY_STATUS="))
	batt_info->status = CS_UNKNOWN;
	else if (BEGINS_WITH(last, "POWER_SUPPLY_CHARGE_FULL_DESIGN=") ||
	BEGINS_WITH(last, "POWER_SUPPLY_ENERGY_FULL_DESIGN="))
	batt_info->full_design = atoi(walk + 1);
	else if (BEGINS_WITH(last, "POWER_SUPPLY_ENERGY_FULL=") ||
	BEGINS_WITH(last, "POWER_SUPPLY_CHARGE_FULL="))
	batt_info->full_last = atoi(walk + 1);
	}