1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/acpi/tables/tbrsdt.c b/drivers/acpi/tables/tbrsdt.c
index b7ffe39c3626..13c6ddb2f546 100644
--- a/drivers/acpi/tables/tbrsdt.c
+++ b/drivers/acpi/tables/tbrsdt.c
@@ -159,8 +159,8 @@ cleanup:
  *
  * RETURN:      None, Address
  *
- * DESCRIPTION: Extract the address of the RSDT or XSDT, depending on the
- *              version of the RSDP
+ * DESCRIPTION: Extract the address of either the RSDT or XSDT, depending on the
+ *              version of the RSDP and whether the XSDT pointer is valid
  *
  ******************************************************************************/
 
@@ -174,16 +174,19 @@ acpi_tb_get_rsdt_address (
 
         out_address->pointer_type = acpi_gbl_table_flags | ACPI_LOGICAL_ADDRESSING;
 
-        /*
-         * For RSDP revision 0 or 1, we use the RSDT.
-         * For RSDP revision 2 (and above), we use the XSDT
-         */
-        if (acpi_gbl_RSDP->revision < 2) {
-                out_address->pointer.value = acpi_gbl_RSDP->rsdt_physical_address;
-        }
-        else {
+        /* Use XSDT if it is present */
+
+        if ((acpi_gbl_RSDP->revision >= 2) &&
+                acpi_gbl_RSDP->xsdt_physical_address) {
                 out_address->pointer.value =
                         acpi_gbl_RSDP->xsdt_physical_address;
+                acpi_gbl_root_table_type = ACPI_TABLE_TYPE_XSDT;
+        }
+        else {
+                /* No XSDT, use the RSDT */
+
+                out_address->pointer.value = acpi_gbl_RSDP->rsdt_physical_address;
+                acpi_gbl_root_table_type = ACPI_TABLE_TYPE_RSDT;
         }
 }
 
@@ -211,10 +214,9 @@ acpi_tb_validate_rsdt (
 
 
         /*
-         * For RSDP revision 0 or 1, we use the RSDT.
-         * For RSDP revision 2 and above, we use the XSDT
+         * Search for appropriate signature, RSDT or XSDT
          */
-        if (acpi_gbl_RSDP->revision < 2) {
+        if (acpi_gbl_root_table_type == ACPI_TABLE_TYPE_RSDT) {
                 no_match = ACPI_STRNCMP ((char *) table_ptr, RSDT_SIG,
                                   sizeof (RSDT_SIG) -1);
         }
@@ -236,11 +238,11 @@ acpi_tb_validate_rsdt (
                         acpi_gbl_RSDP->rsdt_physical_address,
                         (void *) (acpi_native_uint) acpi_gbl_RSDP->rsdt_physical_address));
 
-                if (acpi_gbl_RSDP->revision < 2) {
-                        ACPI_REPORT_ERROR (("Looking for RSDT (RSDP->Rev < 2)\n"))
+                if (acpi_gbl_root_table_type == ACPI_TABLE_TYPE_RSDT) {
+                        ACPI_REPORT_ERROR (("Looking for RSDT\n"))
                 }
                 else {
-                        ACPI_REPORT_ERROR (("Looking for XSDT (RSDP->Rev >= 2)\n"))
+                        ACPI_REPORT_ERROR (("Looking for XSDT\n"))
                 }
 
                 ACPI_DUMP_BUFFER ((char *) table_ptr, 48);