1 files changed, 18 insertions, 5 deletions

diff --git a/drivers/acpi/acpica/tbxface.c b/drivers/acpi/acpica/tbxface.c
index 5217a6159a31..684614d0d327 100644
--- a/drivers/acpi/acpica/tbxface.c
+++ b/drivers/acpi/acpica/tbxface.c
@@ -172,6 +172,7 @@ acpi_status acpi_reallocate_root_table(void)
 {
         struct acpi_table_desc *tables;
         acpi_size new_size;
+        acpi_size current_size;
 
         ACPI_FUNCTION_TRACE(acpi_reallocate_root_table);
 
@@ -183,9 +184,15 @@ acpi_status acpi_reallocate_root_table(void)
                 return_ACPI_STATUS(AE_SUPPORT);
         }
 
-        new_size = ((acpi_size) acpi_gbl_root_table_list.count +
-                    ACPI_ROOT_TABLE_SIZE_INCREMENT) *
-            sizeof(struct acpi_table_desc);
+        /*
+         * Get the current size of the root table and add the default
+         * increment to create the new table size.
+         */
+        current_size = (acpi_size)
+            acpi_gbl_root_table_list.count * sizeof(struct acpi_table_desc);
+
+        new_size = current_size +
+            (ACPI_ROOT_TABLE_SIZE_INCREMENT * sizeof(struct acpi_table_desc));
 
         /* Create new array and copy the old array */
 
@@ -194,10 +201,16 @@ acpi_status acpi_reallocate_root_table(void)
                 return_ACPI_STATUS(AE_NO_MEMORY);
         }
 
-        ACPI_MEMCPY(tables, acpi_gbl_root_table_list.tables, new_size);
+        ACPI_MEMCPY(tables, acpi_gbl_root_table_list.tables, current_size);
 
-        acpi_gbl_root_table_list.size = acpi_gbl_root_table_list.count;
+        /*
+         * Update the root table descriptor. The new size will be the current
+         * number of tables plus the increment, independent of the reserved
+         * size of the original table list.
+         */
         acpi_gbl_root_table_list.tables = tables;
+        acpi_gbl_root_table_list.size =
+            acpi_gbl_root_table_list.count + ACPI_ROOT_TABLE_SIZE_INCREMENT;
         acpi_gbl_root_table_list.flags =
             ACPI_ROOT_ORIGIN_ALLOCATED | ACPI_ROOT_ALLOW_RESIZE;