ACPI: power: don't cache power resource state

ACPI may change power resource state behind our back, so don't
keep our local copy, which may not be valid.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 24 insertions, 39 deletions

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 57b9a2998fd0..af1769a20c7a 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -86,7 +86,6 @@ struct acpi_power_resource {
         acpi_bus_id name;
         u32 system_level;
         u32 order;
-        int state;
         struct mutex resource_lock;
         struct list_head reference;
 };
@@ -128,33 +127,31 @@ acpi_power_get_context(acpi_handle handle,
         return 0;
 }
 
-static int acpi_power_get_state(struct acpi_power_resource *resource)
+static int acpi_power_get_state(struct acpi_power_resource *resource, int *state)
 {
         acpi_status status = AE_OK;
         unsigned long sta = 0;
 
 
-        if (!resource)
+        if (!resource || !state)
                 return -EINVAL;
 
         status = acpi_evaluate_integer(resource->device->handle, "_STA", NULL, &sta);
         if (ACPI_FAILURE(status))
                 return -ENODEV;
 
-        if (sta & 0x01)
-                resource->state = ACPI_POWER_RESOURCE_STATE_ON;
-        else
-                resource->state = ACPI_POWER_RESOURCE_STATE_OFF;
+        *state = (sta & 0x01)?ACPI_POWER_RESOURCE_STATE_ON:
+                              ACPI_POWER_RESOURCE_STATE_OFF;
 
         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] is %s\n",
-                          resource->name, resource->state ? "on" : "off"));
+                          resource->name, state ? "on" : "off"));
 
         return 0;
 }
 
 static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 {
-        int result = 0;
+        int result = 0, state1;
         struct acpi_power_resource *resource = NULL;
         u32 i = 0;
 
@@ -168,11 +165,11 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
                 result = acpi_power_get_context(list->handles[i], &resource);
                 if (result)
                         return result;
-                result = acpi_power_get_state(resource);
+                result = acpi_power_get_state(resource, &state1);
                 if (result)
                         return result;
 
-                *state = resource->state;
+                *state = state1;
 
                 if (*state != ACPI_POWER_RESOURCE_STATE_ON)
                         break;
@@ -186,7 +183,7 @@ static int acpi_power_get_list_state(struct acpi_handle_list *list, int *state)
 
 static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
 {
-        int result = 0;
+        int result = 0, state;
         int found = 0;
         acpi_status status = AE_OK;
         struct acpi_power_resource *resource = NULL;
@@ -224,20 +221,14 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
         }
         mutex_unlock(&resource->resource_lock);
 
-        if (resource->state == ACPI_POWER_RESOURCE_STATE_ON) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already on\n",
-                                  resource->name));
-                return 0;
-        }
-
         status = acpi_evaluate_object(resource->device->handle, "_ON", NULL, NULL);
         if (ACPI_FAILURE(status))
                 return -ENODEV;
 
-        result = acpi_power_get_state(resource);
+        result = acpi_power_get_state(resource, &state);
         if (result)
                 return result;
-        if (resource->state != ACPI_POWER_RESOURCE_STATE_ON)
+        if (state != ACPI_POWER_RESOURCE_STATE_ON)
                 return -ENOEXEC;
 
         /* Update the power resource's _device_ power state */
@@ -250,7 +241,7 @@ static int acpi_power_on(acpi_handle handle, struct acpi_device *dev)
 
 static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
 {
-        int result = 0;
+        int result = 0, state;
         acpi_status status = AE_OK;
         struct acpi_power_resource *resource = NULL;
         struct list_head *node, *next;
@@ -281,20 +272,14 @@ static int acpi_power_off_device(acpi_handle handle, struct acpi_device *dev)
         }
         mutex_unlock(&resource->resource_lock);
 
-        if (resource->state == ACPI_POWER_RESOURCE_STATE_OFF) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Resource [%s] already off\n",
-                                  resource->name));
-                return 0;
-        }
-
         status = acpi_evaluate_object(resource->device->handle, "_OFF", NULL, NULL);
         if (ACPI_FAILURE(status))
                 return -ENODEV;
 
-        result = acpi_power_get_state(resource);
+        result = acpi_power_get_state(resource, &state);
         if (result)
                 return result;
-        if (resource->state != ACPI_POWER_RESOURCE_STATE_OFF)
+        if (state != ACPI_POWER_RESOURCE_STATE_OFF)
                 return -ENOEXEC;
 
         /* Update the power resource's _device_ power state */
@@ -494,7 +479,7 @@ static struct proc_dir_entry *acpi_power_dir;
 static int acpi_power_seq_show(struct seq_file *seq, void *offset)
 {
         int count = 0;
-        int result = 0;
+        int result = 0, state;
         struct acpi_power_resource *resource = NULL;
         struct list_head *node, *next;
         struct acpi_power_reference *ref;
@@ -505,12 +490,12 @@ static int acpi_power_seq_show(struct seq_file *seq, void *offset)
         if (!resource)
                 goto end;
 
-        result = acpi_power_get_state(resource);
+        result = acpi_power_get_state(resource, &state);
         if (result)
                 goto end;
 
         seq_puts(seq, "state:                   ");
-        switch (resource->state) {
+        switch (state) {
         case ACPI_POWER_RESOURCE_STATE_ON:
                 seq_puts(seq, "on\n");
                 break;
@@ -591,7 +576,7 @@ static int acpi_power_remove_fs(struct acpi_device *device)
 
 static int acpi_power_add(struct acpi_device *device)
 {
-        int result = 0;
+        int result = 0, state;
         acpi_status status = AE_OK;
         struct acpi_power_resource *resource = NULL;
         union acpi_object acpi_object;
@@ -622,11 +607,11 @@ static int acpi_power_add(struct acpi_device *device)
         resource->system_level = acpi_object.power_resource.system_level;
         resource->order = acpi_object.power_resource.resource_order;
 
-        result = acpi_power_get_state(resource);
+        result = acpi_power_get_state(resource, &state);
         if (result)
                 goto end;
 
-        switch (resource->state) {
+        switch (state) {
         case ACPI_POWER_RESOURCE_STATE_ON:
                 device->power.state = ACPI_STATE_D0;
                 break;
@@ -643,7 +628,7 @@ static int acpi_power_add(struct acpi_device *device)
                 goto end;
 
         printk(KERN_INFO PREFIX "%s [%s] (%s)\n", acpi_device_name(device),
-               acpi_device_bid(device), resource->state ? "on" : "off");
+               acpi_device_bid(device), state ? "on" : "off");
 
       end:
         if (result)
@@ -680,7 +665,7 @@ static int acpi_power_remove(struct acpi_device *device, int type)
 
 static int acpi_power_resume(struct acpi_device *device)
 {
-        int result = 0;
+        int result = 0, state;
         struct acpi_power_resource *resource = NULL;
         struct acpi_power_reference *ref;
 
@@ -689,12 +674,12 @@ static int acpi_power_resume(struct acpi_device *device)
 
         resource = (struct acpi_power_resource *)acpi_driver_data(device);
 
-        result = acpi_power_get_state(resource);
+        result = acpi_power_get_state(resource, &state);
         if (result)
                 return result;
 
         mutex_lock(&resource->resource_lock);
-        if ((resource->state == ACPI_POWER_RESOURCE_STATE_OFF) &&
+        if (state == ACPI_POWER_RESOURCE_STATE_OFF &&
             !list_empty(&resource->reference)) {
                 ref = container_of(resource->reference.next, struct acpi_power_reference, node);
                 mutex_unlock(&resource->resource_lock);