ACPICA: Add repair for bad _MAT buffers

_MAT can inadvertently return an Integer instead of a Buffer
if the return value has been read from a Field whose width is
less than or equal to the global integer width (32 or 64 bits).
ACPICA BZ 810.

http://www.acpica.org/bugzilla/show_bug.cgi?id=810

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/acpica/nsrepair.c b/drivers/acpi/acpica/nsrepair.c
index dfa31c5ba6c3424b8a97e0dd0b47c4c99d0bb559..f2f5269fed6dc8cc2f44c81de8833f2e22ff48da 100644 (file)
--- a/drivers/acpi/acpica/nsrepair.c
+++ b/drivers/acpi/acpica/nsrepair.c
@@ -44,6 +44,7 @@
 #include <acpi/acpi.h>
 #include "accommon.h"
 #include "acnamesp.h"
+#include "acinterp.h"
 #include "acpredef.h"
 
 #define _COMPONENT          ACPI_NAMESPACE
@@ -76,6 +77,7 @@ acpi_ns_repair_object(struct acpi_predefined_data *data,
        union acpi_operand_object *return_object = *return_object_ptr;
        union acpi_operand_object *new_object;
        acpi_size length;
+       acpi_status status;
 
        /*
         * At this point, we know that the type of the returned object was not
@@ -120,9 +122,26 @@ acpi_ns_repair_object(struct acpi_predefined_data *data,
 
        case ACPI_TYPE_INTEGER:
 
-               /* Does the method/object legally return a string? */
+               /* 1) Does the method/object legally return a buffer? */
+
+               if (expected_btypes & ACPI_RTYPE_BUFFER) {
+                       /*
+                        * Convert the Integer to a packed-byte buffer. _MAT needs
+                        * this sometimes, if a read has been performed on a Field
+                        * object that is less than or equal to the global integer
+                        * size (32 or 64 bits).
+                        */
+                       status =
+                           acpi_ex_convert_to_buffer(return_object,
+                                                     &new_object);
+                       if (ACPI_FAILURE(status)) {
+                               return (status);
+                       }
+               }
+
+               /* 2) Does the method/object legally return a string? */
 
-               if (expected_btypes & ACPI_RTYPE_STRING) {
+               else if (expected_btypes & ACPI_RTYPE_STRING) {
                        /*
                         * The only supported Integer-to-String conversion is to convert
                         * an integer of value 0 to a NULL string. The last element of