Commit 4c41d3ad authored Nov 07, 2007 by Roland Dreier Committed by Len Brown Nov 08, 2007

ACPI: Always return valid 'status' from acpi_battery_get_property()



If a battery is at a critical charge level and not being charged or
discharged, then the ACPI _BST method will return a state of 4, and
the current acpi_battery_get_property() code will not set any property
value for POWER_SUPPLY_PROP_STATUS.  This will cause an oops in
power_supply_show_property() when it reads off the end of the
status_text array.  This actually was causing a 100% reproducible
crash on boot on my laptop with two batteries, when one battery was
completely drained and the laptop was not plugged in.

Fix this by making sure acpi_battery_get_property() returns
POWER_SUPPLY_STATUS_UNKNOWN for any battery state it doesn't already
handle explicitly.  There doesn't seem to be any status enum value
defined that makes more sense than 'unknown' for a battery at a
critical charge level.

Signed-off-by: Roland Dreier <roland@digitalvampire.org>
Acked-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <lenb@t61.(none)>

parent dbeeb816

drivers/acpi/battery.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -152,6 +152,8 @@ static int acpi_battery_get_property(struct power_supply *psy,
		val->intval = POWER_SUPPLY_STATUS_CHARGING;
		else if (battery->state == 0)
		val->intval = POWER_SUPPLY_STATUS_FULL;
		else
		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
		break;
		case POWER_SUPPLY_PROP_PRESENT:
		val->intval = acpi_battery_present(battery);

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