[PATCH 7/13] ACPI / PM: Add function for device power state initialization

Rafael J. Wysocki
2010-11-24T23:08:36Z

Add function acpi_bus_init_power() for getting the initial power
state of an ACPI device and reference counting its power resources
as appropriate.

Make acpi_bus_get_power_flags() use the new function instead of
acpi_bus_get_power() that updates device->power.state without
reference counting the device's power resources.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
drivers/acpi/bus.c | 25 +++++++++++++++++++++++++
drivers/acpi/internal.h | 1 +
drivers/acpi/scan.c | 5 +----
3 files changed, 27 insertions(+), 4 deletions(-)

Index: linux-2.6/drivers/acpi/bus.c
===================================================================
--- linux-2.6.orig/drivers/acpi/bus.c
+++ linux-2.6/drivers/acpi/bus.c
@@ -364,6 +364,31 @@ int acpi_bus_set_power(acpi_handle handl

EXPORT_SYMBOL(acpi_bus_set_power);

+
+int acpi_bus_init_power(struct acpi_device *device)
+{
+ int state;
+ int result;
+
+ if (!device)
+ return -EINVAL;
+
+ device->power.state = ACPI_STATE_UNKNOWN;
+
+ result = __acpi_bus_get_power(device, &state);
+ if (result)
+ return result;
+
+ if (device->power.flags.power_resources)
+ result = acpi_power_on_resources(device, state);
+
+ if (!result)
+ device->power.state = state;
+
+ return result;
+}
+
+
bool acpi_bus_power_manageable(acpi_handle handle)
{
struct acpi_device *device;
Index: linux-2.6/drivers/acpi/scan.c
===================================================================
--- linux-2.6.orig/drivers/acpi/scan.c
+++ linux-2.6/drivers/acpi/scan.c
@@ -881,10 +881,7 @@ static int acpi_bus_get_power_flags(stru
device->power.states[ACPI_STATE_D3].flags.valid = 1;
device->power.states[ACPI_STATE_D3].power = 0;

- /* TBD: System wake support and resource requirements. */
-
- device->power.state = ACPI_STATE_UNKNOWN;
- acpi_bus_get_power(device->handle, &(device->power.state));
+ acpi_bus_init_power(device);

return 0;
}
Index: linux-2.6/drivers/acpi/internal.h
===================================================================
--- linux-2.6.orig/drivers/acpi/internal.h
+++ linux-2.6/drivers/acpi/internal.h
@@ -44,6 +44,7 @@ int acpi_device_sleep_wake(struct acpi_d
int acpi_power_get_inferred_state(struct acpi_device *device, int *state);
int acpi_power_on_resources(struct acpi_device *device, int state);
int acpi_power_transition(struct acpi_device *device, int state);
+int acpi_bus_init_power(struct acpi_device *device);
extern int acpi_power_nocheck;

int acpi_wakeup_device_init(void);