diff options
Diffstat (limited to 'drivers/acpi/bus.c')
| -rw-r--r-- | drivers/acpi/bus.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index d59175efc428..1f0d457ecbcf 100644 --- a/drivers/acpi/bus.c +++ b/drivers/acpi/bus.c @@ -257,7 +257,15 @@ static int __acpi_bus_get_power(struct acpi_device *device, int *state) } -static int __acpi_bus_set_power(struct acpi_device *device, int state) +/** + * acpi_device_set_power - Set power state of an ACPI device. + * @device: Device to set the power state of. + * @state: New power state to set. + * + * Callers must ensure that the device is power manageable before using this + * function. + */ +int acpi_device_set_power(struct acpi_device *device, int state) { int result = 0; acpi_status status = AE_OK; @@ -298,6 +306,12 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state) * a lower-powered state. */ if (state < device->power.state) { + if (device->power.state >= ACPI_STATE_D3_HOT && + state != ACPI_STATE_D0) { + printk(KERN_WARNING PREFIX + "Cannot transition to non-D0 state from D3\n"); + return -ENODEV; + } if (device->power.flags.power_resources) { result = acpi_power_transition(device, state); if (result) @@ -341,6 +355,7 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state) return result; } +EXPORT_SYMBOL(acpi_device_set_power); int acpi_bus_set_power(acpi_handle handle, int state) @@ -359,7 +374,7 @@ int acpi_bus_set_power(acpi_handle handle, int state) return -ENODEV; } - return __acpi_bus_set_power(device, state); + return acpi_device_set_power(device, state); } EXPORT_SYMBOL(acpi_bus_set_power); @@ -402,7 +417,7 @@ int acpi_bus_update_power(acpi_handle handle, int *state_p) if (result) return result; - result = __acpi_bus_set_power(device, state); + result = acpi_device_set_power(device, state); if (!result && state_p) *state_p = state; |