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-rw-r--r--drivers/acpi/power.c67
1 files changed, 38 insertions, 29 deletions
diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 9bd1b6044b5..95fedbdf4fb 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -266,6 +266,35 @@ static int acpi_power_off_device(acpi_handle handle)
return result;
}
+static void __acpi_power_off_list(struct acpi_handle_list *list, int num_res)
+{
+ int i;
+
+ for (i = num_res - 1; i >= 0 ; i--)
+ acpi_power_off_device(list->handles[i]);
+}
+
+static void acpi_power_off_list(struct acpi_handle_list *list)
+{
+ __acpi_power_off_list(list, list->count);
+}
+
+static int acpi_power_on_list(struct acpi_handle_list *list)
+{
+ int result = 0;
+ int i;
+
+ for (i = 0; i < list->count; i++) {
+ result = acpi_power_on(list->handles[i]);
+ if (result) {
+ __acpi_power_off_list(list, i);
+ break;
+ }
+ }
+
+ return result;
+}
+
/**
* acpi_device_sleep_wake - execute _DSW (Device Sleep Wake) or (deprecated in
* ACPI 3.0) _PSW (Power State Wake)
@@ -458,10 +487,7 @@ int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
int acpi_power_transition(struct acpi_device *device, int state)
{
- int result = 0;
- struct acpi_handle_list *cl = NULL; /* Current Resources */
- struct acpi_handle_list *tl = NULL; /* Target Resources */
- int i = 0;
+ int result;
if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
return -EINVAL;
@@ -473,37 +499,20 @@ int acpi_power_transition(struct acpi_device *device, int state)
|| (device->power.state > ACPI_STATE_D3))
return -ENODEV;
- cl = &device->power.states[device->power.state].resources;
- tl = &device->power.states[state].resources;
-
/* TBD: Resources must be ordered. */
/*
* First we reference all power resources required in the target list
- * (e.g. so the device doesn't lose power while transitioning).
+ * (e.g. so the device doesn't lose power while transitioning). Then,
+ * we dereference all power resources used in the current list.
*/
- for (i = 0; i < tl->count; i++) {
- result = acpi_power_on(tl->handles[i]);
- if (result)
- goto end;
- }
+ result = acpi_power_on_list(&device->power.states[state].resources);
+ if (!result)
+ acpi_power_off_list(
+ &device->power.states[device->power.state].resources);
- /*
- * Then we dereference all power resources used in the current list.
- */
- for (i = 0; i < cl->count; i++) {
- result = acpi_power_off_device(cl->handles[i]);
- if (result)
- goto end;
- }
-
- end:
- if (result)
- device->power.state = ACPI_STATE_UNKNOWN;
- else {
- /* We shouldn't change the state till all above operations succeed */
- device->power.state = state;
- }
+ /* We shouldn't change the state unless the above operations succeed. */
+ device->power.state = result ? ACPI_STATE_UNKNOWN : state;
return result;
}