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;