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path: root/drivers/acpi/bus.c
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Diffstat (limited to 'drivers/acpi/bus.c')
-rw-r--r--drivers/acpi/bus.c88
1 files changed, 57 insertions, 31 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 3188da3df8da..adceafda9c17 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -182,41 +182,66 @@ EXPORT_SYMBOL(acpi_bus_get_private_data);
Power Management
-------------------------------------------------------------------------- */
+static const char *state_string(int state)
+{
+ switch (state) {
+ case ACPI_STATE_D0:
+ return "D0";
+ case ACPI_STATE_D1:
+ return "D1";
+ case ACPI_STATE_D2:
+ return "D2";
+ case ACPI_STATE_D3_HOT:
+ return "D3hot";
+ case ACPI_STATE_D3_COLD:
+ return "D3";
+ default:
+ return "(unknown)";
+ }
+}
+
static int __acpi_bus_get_power(struct acpi_device *device, int *state)
{
- int result = 0;
- acpi_status status = 0;
- unsigned long long psc = 0;
+ int result = ACPI_STATE_UNKNOWN;
if (!device || !state)
return -EINVAL;
- *state = ACPI_STATE_UNKNOWN;
-
- if (device->flags.power_manageable) {
- /*
- * Get the device's power state either directly (via _PSC) or
- * indirectly (via power resources).
- */
- if (device->power.flags.power_resources) {
- result = acpi_power_get_inferred_state(device, state);
- if (result)
- return result;
- } else if (device->power.flags.explicit_get) {
- status = acpi_evaluate_integer(device->handle, "_PSC",
- NULL, &psc);
- if (ACPI_FAILURE(status))
- return -ENODEV;
- *state = (int)psc;
- }
- } else {
+ if (!device->flags.power_manageable) {
/* TBD: Non-recursive algorithm for walking up hierarchy. */
*state = device->parent ?
device->parent->power.state : ACPI_STATE_D0;
+ goto out;
+ }
+
+ /*
+ * Get the device's power state either directly (via _PSC) or
+ * indirectly (via power resources).
+ */
+ if (device->power.flags.explicit_get) {
+ unsigned long long psc;
+ acpi_status status = acpi_evaluate_integer(device->handle,
+ "_PSC", NULL, &psc);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ result = psc;
+ }
+ /* The test below covers ACPI_STATE_UNKNOWN too. */
+ if (result <= ACPI_STATE_D2) {
+ ; /* Do nothing. */
+ } else if (device->power.flags.power_resources) {
+ int error = acpi_power_get_inferred_state(device, &result);
+ if (error)
+ return error;
+ } else if (result == ACPI_STATE_D3_HOT) {
+ result = ACPI_STATE_D3;
}
+ *state = result;
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is D%d\n",
- device->pnp.bus_id, *state));
+ out:
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
+ device->pnp.bus_id, state_string(*state)));
return 0;
}
@@ -234,13 +259,14 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
/* Make sure this is a valid target state */
if (state == device->power.state) {
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at D%d\n",
- state));
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device is already at %s\n",
+ state_string(state)));
return 0;
}
if (!device->power.states[state].flags.valid) {
- printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
+ printk(KERN_WARNING PREFIX "Device does not support %s\n",
+ state_string(state));
return -ENODEV;
}
if (device->parent && (state < device->parent->power.state)) {
@@ -294,13 +320,13 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
end:
if (result)
printk(KERN_WARNING PREFIX
- "Device [%s] failed to transition to D%d\n",
- device->pnp.bus_id, state);
+ "Device [%s] failed to transition to %s\n",
+ device->pnp.bus_id, state_string(state));
else {
device->power.state = state;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
- "Device [%s] transitioned to D%d\n",
- device->pnp.bus_id, state));
+ "Device [%s] transitioned to %s\n",
+ device->pnp.bus_id, state_string(state)));
}
return result;