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authorRafael J. Wysocki <rjw@sisk.pl>2010-11-25 00:09:15 +0100
committerLen Brown <len.brown@intel.com>2011-01-12 04:48:45 -0500
commit25eed40720fc9005c63a1f436e5f8a78836c26ff (patch)
tree2c927e50d57c2e456d9ceaa575c1bb774627ee10 /drivers/acpi
parentade3e7fef794781c0798d0cf0f046123842ba550 (diff)
ACPI / PM: Add function for updating device power state consistently
Add function acpi_bus_update_power() for reading the actual power state of an ACPI device and updating its device->power.state field in such a way that its power resources' reference counters will remain consistent with that field. For this purpose introduce __acpi_bus_set_power() setting the power state of an ACPI device without updating its device->power.state field and make acpi_bus_set_power() and acpi_bus_update_power() use it (acpi_bus_set_power() retains the current behavior for now). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/bus.c90
1 files changed, 61 insertions, 29 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 45345109050..19decee72e9 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -255,44 +255,17 @@ int acpi_bus_get_power(acpi_handle handle, int *state)
EXPORT_SYMBOL(acpi_bus_get_power);
-int acpi_bus_set_power(acpi_handle handle, int state)
+static int __acpi_bus_set_power(struct acpi_device *device, int state)
{
int result = 0;
acpi_status status = AE_OK;
- struct acpi_device *device = NULL;
char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
-
- result = acpi_bus_get_device(handle, &device);
- if (result)
- return result;
-
- if ((state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
+ if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
return -EINVAL;
/* Make sure this is a valid target state */
- if (!device->flags.power_manageable) {
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device `[%s]' is not power manageable\n",
- kobject_name(&device->dev.kobj)));
- return -ENODEV;
- }
- /*
- * Get device's current power state
- */
- if (!acpi_power_nocheck) {
- /*
- * Maybe the incorrect power state is returned on the bogus
- * bios, which is different with the real power state.
- * For example: the bios returns D0 state and the real power
- * state is D3. OS expects to set the device to D0 state. In
- * such case if OS uses the power state returned by the BIOS,
- * the device can't be transisted to the correct power state.
- * So if the acpi_power_nocheck is set, it is unnecessary to
- * get the power state by calling acpi_bus_get_power.
- */
- acpi_bus_get_power(device->handle, &device->power.state);
- }
if ((state == device->power.state) && !device->flags.force_power_state) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
state));
@@ -362,6 +335,42 @@ int acpi_bus_set_power(acpi_handle handle, int state)
return result;
}
+
+int acpi_bus_set_power(acpi_handle handle, int state)
+{
+ struct acpi_device *device;
+ int result;
+
+ result = acpi_bus_get_device(handle, &device);
+ if (result)
+ return result;
+
+ if (!device->flags.power_manageable) {
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "Device [%s] is not power manageable\n",
+ dev_name(&device->dev)));
+ return -ENODEV;
+ }
+
+ /*
+ * Get device's current power state
+ */
+ if (!acpi_power_nocheck) {
+ /*
+ * Maybe the incorrect power state is returned on the bogus
+ * bios, which is different with the real power state.
+ * For example: the bios returns D0 state and the real power
+ * state is D3. OS expects to set the device to D0 state. In
+ * such case if OS uses the power state returned by the BIOS,
+ * the device can't be transisted to the correct power state.
+ * So if the acpi_power_nocheck is set, it is unnecessary to
+ * get the power state by calling acpi_bus_get_power.
+ */
+ __acpi_bus_get_power(device, &device->power.state);
+ }
+
+ return __acpi_bus_set_power(device, state);
+}
EXPORT_SYMBOL(acpi_bus_set_power);
@@ -389,6 +398,29 @@ int acpi_bus_init_power(struct acpi_device *device)
}
+int acpi_bus_update_power(acpi_handle handle, int *state_p)
+{
+ struct acpi_device *device;
+ int state;
+ int result;
+
+ result = acpi_bus_get_device(handle, &device);
+ if (result)
+ return result;
+
+ result = __acpi_bus_get_power(device, &state);
+ if (result)
+ return result;
+
+ result = __acpi_bus_set_power(device, state);
+ if (!result && state_p)
+ *state_p = state;
+
+ return result;
+}
+EXPORT_SYMBOL_GPL(acpi_bus_update_power);
+
+
bool acpi_bus_power_manageable(acpi_handle handle)
{
struct acpi_device *device;