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authorRafael J. Wysocki <rjw@sisk.pl>2010-11-25 00:06:09 +0100
committerLen Brown <len.brown@intel.com>2011-01-12 04:48:43 -0500
commitd2ef555b57292cd818934636ac8e3414cc2a6762 (patch)
tree6fbe86ad458f20f146dbfb22d624052c644f9ac0 /drivers/acpi
parent32a00d274e877eab3ea7ab196b75c9be5170d25e (diff)
ACPI / PM: Add functions for manipulating lists of power resources
ACPI device power resources should be reference counted during device initialization, so that their reference counters are always up to date. It is convenient to do that with the help of a function that will reference count and possibly turn on power resources in a given list, so introduce that function, acpi_power_on_list(). For symmetry, introduce acpi_power_off_list() for performing the reverse operation and use the both of them to simplify acpi_power_transition(). 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/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;
}