ACPICA: Fix for Alias operator to see target child objects

Fixed a problem with the Alias operator when the target of the
alias is a named ASL operator that opens a new scope -- Scope,
Device, PowerResource, Processor, and ThermalZone. In these cases,
any children of the original operator could not be accessed via
the alias, potentially causing unexpected AE_NOT_FOUND exceptions.

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

1 files changed, 15 insertions, 5 deletions

diff --git a/drivers/acpi/executer/excreate.c b/drivers/acpi/executer/excreate.c
index 6e9a23e47fef..b3914395851b 100644
--- a/drivers/acpi/executer/excreate.c
+++ b/drivers/acpi/executer/excreate.c
@@ -96,6 +96,9 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
          * to the original Node.
          */
         switch (target_node->type) {
+
+                /* For these types, the sub-object can change dynamically via a Store */
+
         case ACPI_TYPE_INTEGER:
         case ACPI_TYPE_STRING:
         case ACPI_TYPE_BUFFER:
@@ -103,9 +106,18 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
         case ACPI_TYPE_BUFFER_FIELD:
 
                 /*
+                 * These types open a new scope, so we need the NS node in order to access
+                 * any children.
+                 */
+        case ACPI_TYPE_DEVICE:
+        case ACPI_TYPE_POWER:
+        case ACPI_TYPE_PROCESSOR:
+        case ACPI_TYPE_THERMAL:
+        case ACPI_TYPE_LOCAL_SCOPE:
+
+                /*
                  * The new alias has the type ALIAS and points to the original
-                 * NS node, not the object itself.  This is because for these
-                 * types, the object can change dynamically via a Store.
+                 * NS node, not the object itself.
                  */
                 alias_node->type = ACPI_TYPE_LOCAL_ALIAS;
                 alias_node->object =
@@ -115,9 +127,7 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
         case ACPI_TYPE_METHOD:
 
                 /*
-                 * The new alias has the type ALIAS and points to the original
-                 * NS node, not the object itself.  This is because for these
-                 * types, the object can change dynamically via a Store.
+                 * Control method aliases need to be differentiated
                  */
                 alias_node->type = ACPI_TYPE_LOCAL_METHOD_ALIAS;
                 alias_node->object =