1 files changed, 92 insertions, 66 deletions

diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index afc808e93855..fd363b57a596 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -403,44 +403,37 @@ EXPORT_SYMBOL(acpi_bus_can_wakeup);
  * @dev: Device whose preferred target power state to return.
  * @adev: ACPI device node corresponding to @dev.
  * @target_state: System state to match the resultant device state.
- * @d_max_in: Deepest low-power state to take into consideration.
- * @d_min_p: Location to store the upper limit of the allowed states range.
- * Return value: Preferred power state of the device on success, -ENODEV
- * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ * @d_min_p: Location to store the highest power state available to the device.
+ * @d_max_p: Location to store the lowest power state available to the device.
  *
- * Find the lowest power (highest number) ACPI device power state that the
- * device can be in while the system is in the state represented by
- * @target_state.  If @d_min_p is set, the highest power (lowest number) device
- * power state that @dev can be in for the given system sleep state is stored
- * at the location pointed to by it.
+ * Find the lowest power (highest number) and highest power (lowest number) ACPI
+ * device power states that the device can be in while the system is in the
+ * state represented by @target_state.  Store the integer numbers representing
+ * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
+ * respectively.
  *
  * Callers must ensure that @dev and @adev are valid pointers and that @adev
  * actually corresponds to @dev before using this function.
+ *
+ * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
+ * returns a value that doesn't make sense.  The memory locations pointed to by
+ * @d_max_p and @d_min_p are only modified on success.
  */
 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
-                                 u32 target_state, int d_max_in, int *d_min_p)
+                                 u32 target_state, int *d_min_p, int *d_max_p)
 {
-        char acpi_method[] = "_SxD";
-        unsigned long long d_min, d_max;
+        char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
+        acpi_handle handle = adev->handle;
+        unsigned long long ret;
+        int d_min, d_max;
         bool wakeup = false;
+        acpi_status status;
 
-        if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
-                return -EINVAL;
-
-        if (d_max_in > ACPI_STATE_D3_HOT) {
-                enum pm_qos_flags_status stat;
-
-                stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
-                if (stat == PM_QOS_FLAGS_ALL)
-                        d_max_in = ACPI_STATE_D3_HOT;
-        }
-
-        acpi_method[2] = '0' + target_state;
         /*
-         * If the sleep state is S0, the lowest limit from ACPI is D3,
-         * but if the device has _S0W, we will use the value from _S0W
-         * as the lowest limit from ACPI.  Finally, we will constrain
-         * the lowest limit with the specified one.
+         * If the system state is S0, the lowest power state the device can be
+         * in is D3cold, unless the device has _S0W and is supposed to signal
+         * wakeup, in which case the return value of _S0W has to be used as the
+         * lowest power state available to the device.
          */
         d_min = ACPI_STATE_D0;
         d_max = ACPI_STATE_D3_COLD;
@@ -449,12 +442,30 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
          * If present, _SxD methods return the minimum D-state (highest power
          * state) we can use for the corresponding S-states.  Otherwise, the
          * minimum D-state is D0 (ACPI 3.x).
-         *
-         * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
-         * provided -- that's our fault recovery, we ignore retval.
          */
         if (target_state > ACPI_STATE_S0) {
-                acpi_evaluate_integer(adev->handle, acpi_method, NULL, &d_min);
+                /*
+                 * We rely on acpi_evaluate_integer() not clobbering the integer
+                 * provided if AE_NOT_FOUND is returned.
+                 */
+                ret = d_min;
+                status = acpi_evaluate_integer(handle, method, NULL, &ret);
+                if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
+                    || ret > ACPI_STATE_D3_COLD)
+                        return -ENODATA;
+
+                /*
+                 * We need to handle legacy systems where D3hot and D3cold are
+                 * the same and 3 is returned in both cases, so fall back to
+                 * D3cold if D3hot is not a valid state.
+                 */
+                if (!adev->power.states[ret].flags.valid) {
+                        if (ret == ACPI_STATE_D3_HOT)
+                                ret = ACPI_STATE_D3_COLD;
+                        else
+                                return -ENODATA;
+                }
+                d_min = ret;
                 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
                         && adev->wakeup.sleep_state >= target_state;
         } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) !=
@@ -470,36 +481,29 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
          * can wake the system.  _S0W may be valid, too.
          */
         if (wakeup) {
-                acpi_status status;
-
-                acpi_method[3] = 'W';
-                status = acpi_evaluate_integer(adev->handle, acpi_method, NULL,
-                                                &d_max);
-                if (ACPI_FAILURE(status)) {
-                        if (target_state != ACPI_STATE_S0 ||
-                            status != AE_NOT_FOUND)
+                method[3] = 'W';
+                status = acpi_evaluate_integer(handle, method, NULL, &ret);
+                if (status == AE_NOT_FOUND) {
+                        if (target_state > ACPI_STATE_S0)
                                 d_max = d_min;
-                } else if (d_max < d_min) {
-                        /* Warn the user of the broken DSDT */
-                        printk(KERN_WARNING "ACPI: Wrong value from %s\n",
-                                acpi_method);
-                        /* Sanitize it */
-                        d_min = d_max;
+                } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
+                        /* Fall back to D3cold if ret is not a valid state. */
+                        if (!adev->power.states[ret].flags.valid)
+                                ret = ACPI_STATE_D3_COLD;
+
+                        d_max = ret > d_min ? ret : d_min;
+                } else {
+                        return -ENODATA;
                 }
         }
 
-        if (d_max_in < d_min)
-                return -EINVAL;
         if (d_min_p)
                 *d_min_p = d_min;
-        /* constrain d_max with specified lowest limit (max number) */
-        if (d_max > d_max_in) {
-                for (d_max = d_max_in; d_max > d_min; d_max--) {
-                        if (adev->power.states[d_max].flags.valid)
-                                break;
-                }
-        }
-        return d_max;
+
+        if (d_max_p)
+                *d_max_p = d_max;
+
+        return 0;
 }
 
 /**
@@ -508,7 +512,8 @@ static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
  * @d_min_p: Location to store the upper limit of the allowed states range.
  * @d_max_in: Deepest low-power state to take into consideration.
  * Return value: Preferred power state of the device on success, -ENODEV
- * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
+ * incorrect, or -ENODATA on ACPI method failure.
  *
  * The caller must ensure that @dev is valid before using this function.
  */
@@ -516,14 +521,39 @@ int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
 {
         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
         struct acpi_device *adev;
+        int ret, d_max;
+
+        if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
+                return -EINVAL;
+
+        if (d_max_in > ACPI_STATE_D3_HOT) {
+                enum pm_qos_flags_status stat;
+
+                stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
+                if (stat == PM_QOS_FLAGS_ALL)
+                        d_max_in = ACPI_STATE_D3_HOT;
+        }
 
         if (!handle || acpi_bus_get_device(handle, &adev)) {
                 dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
                 return -ENODEV;
         }
 
-        return acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
-                                     d_max_in, d_min_p);
+        ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
+                                    d_min_p, &d_max);
+        if (ret)
+                return ret;
+
+        if (d_max_in < *d_min_p)
+                return -EINVAL;
+
+        if (d_max > d_max_in) {
+                for (d_max = d_max_in; d_max > *d_min_p; d_max--) {
+                        if (adev->power.states[d_max].flags.valid)
+                                break;
+                }
+        }
+        return d_max;
 }
 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 
@@ -674,17 +704,13 @@ struct acpi_device *acpi_dev_pm_get_node(struct device *dev)
 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
                                  u32 system_state)
 {
-        int power_state;
+        int ret, state;
 
         if (!acpi_device_power_manageable(adev))
                 return 0;
 
-        power_state = acpi_dev_pm_get_state(dev, adev, system_state,
-                                            ACPI_STATE_D3_COLD, NULL);
-        if (power_state < ACPI_STATE_D0 || power_state > ACPI_STATE_D3_COLD)
-                return -EIO;
-
-        return acpi_device_set_power(adev, power_state);
+        ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
+        return ret ? ret : acpi_device_set_power(adev, state);
 }
 
 /**