diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c index 366ca40a6f703433efc1016a658eaac9e28c5c48..b1df4eee8657b6d6f0b3c27331e0bfa6901350f0 100644 --- a/drivers/acpi/sbs.c +++ b/drivers/acpi/sbs.c @@ -109,6 +109,7 @@ struct acpi_sbs { u8 batteries_supported:4; u8 manager_present:1; u8 charger_present:1; + u8 charger_exists:1; }; #define to_acpi_sbs(x) container_of(x, struct acpi_sbs, charger) @@ -429,9 +430,19 @@ static int acpi_ac_get_present(struct acpi_sbs *sbs) result = acpi_smbus_read(sbs->hc, SMBUS_READ_WORD, ACPI_SBS_CHARGER, 0x13, (u8 *) & status); - if (!result) - sbs->charger_present = (status >> 15) & 0x1; - return result; + + if (result) + return result; + + /* + * The spec requires that bit 4 always be 1. If it's not set, assume + * that the implementation doesn't support an SBS charger + */ + if (!(status >> 4) & 0x1) + return -ENODEV; + + sbs->charger_present = (status >> 15) & 0x1; + return 0; } static ssize_t acpi_battery_alarm_show(struct device *dev, @@ -554,6 +565,7 @@ static int acpi_charger_add(struct acpi_sbs *sbs) if (result) goto end; + sbs->charger_exists = 1; sbs->charger.name = "sbs-charger"; sbs->charger.type = POWER_SUPPLY_TYPE_MAINS; sbs->charger.properties = sbs_ac_props; @@ -580,9 +592,12 @@ static void acpi_sbs_callback(void *context) struct acpi_battery *bat; u8 saved_charger_state = sbs->charger_present; u8 saved_battery_state; - acpi_ac_get_present(sbs); - if (sbs->charger_present != saved_charger_state) - kobject_uevent(&sbs->charger.dev->kobj, KOBJ_CHANGE); + + if (sbs->charger_exists) { + acpi_ac_get_present(sbs); + if (sbs->charger_present != saved_charger_state) + kobject_uevent(&sbs->charger.dev->kobj, KOBJ_CHANGE); + } if (sbs->manager_present) { for (id = 0; id < MAX_SBS_BAT; ++id) { @@ -619,7 +634,7 @@ static int acpi_sbs_add(struct acpi_device *device) device->driver_data = sbs; result = acpi_charger_add(sbs); - if (result) + if (result && result != -ENODEV) goto end; result = acpi_manager_get_info(sbs);