diff -u -r linux-2.4.20+acpi-20021205/Documentation/Configure.help linux-2.4.20+acpi-20021205+rick/Documentation/Configure.help
--- linux-2.4.20+acpi-20021205/Documentation/Configure.help	2002-12-12 14:25:15.000000000 -0600
+++ linux-2.4.20+acpi-20021205+rick/Documentation/Configure.help	2002-12-12 13:42:40.000000000 -0600
@@ -18406,6 +18406,14 @@
   of verbosity. Saying Y enables these statements. This will increase
   your kernel size by around 50K.
 
+ACPI Relaxed AML Checking
+CONFIG_ACPI_RELAXED_AML
+  If you say `Y' here, the ACPI interpreter will relax its checking
+  for valid AML and will ignore some AML mistakes, such as off-by-one
+  errors in region sizes.  Some laptps may require this option.  In
+  particular, many Toshiba laptops require this for correct operation
+  of the AC module.
+
 ACPI Bus Manager
 CONFIG_ACPI_BUSMGR
   The ACPI Bus Manager enumerates devices in the ACPI namespace, and
diff -u -r linux-2.4.20+acpi-20021205/drivers/acpi/Config.in linux-2.4.20+acpi-20021205+rick/drivers/acpi/Config.in
--- linux-2.4.20+acpi-20021205/drivers/acpi/Config.in	2002-12-07 08:11:29.000000000 -0600
+++ linux-2.4.20+acpi-20021205+rick/drivers/acpi/Config.in	2002-12-12 13:31:23.000000000 -0600
@@ -36,6 +36,7 @@
       fi
       tristate     '  Toshiba Laptop Extras'	CONFIG_ACPI_TOSHIBA
       bool         '  Debug Statements'	CONFIG_ACPI_DEBUG
+      bool         '  Relaxed AML Checking'	CONFIG_ACPI_RELAXED_AML
     fi
   fi
 
diff -u -r linux-2.4.20+acpi-20021205/drivers/acpi/executer/exfldio.c linux-2.4.20+acpi-20021205+rick/drivers/acpi/executer/exfldio.c
--- linux-2.4.20+acpi-20021205/drivers/acpi/executer/exfldio.c	2002-12-07 08:11:30.000000000 -0600
+++ linux-2.4.20+acpi-20021205+rick/drivers/acpi/executer/exfldio.c	2002-12-13 13:18:28.000000000 -0600
@@ -121,7 +121,41 @@
 			field_datum_byte_offset, obj_desc->common_field.access_byte_width,
 			rgn_desc->region.node->name.ascii, rgn_desc->region.length));
 
-		return_ACPI_STATUS (AE_AML_REGION_LIMIT);
+		#ifdef CONFIG_ACPI_RELAXED_AML
+		{
+			/*
+			 * Allow access to the field if it is within the region size
+			 * rounded up to a multiple of the access byte width.  This
+			 * overcomes "off-by-one" programming errors in the AML often
+			 * found in Toshiba laptops.  These errors were allowed by
+			 * the Microsoft ASL compiler.
+			 */
+			u32 rounded_length = ACPI_ROUND_UP(rgn_desc->region.length,
+									obj_desc->common_field.access_byte_width);
+
+			if (rounded_length < (obj_desc->common_field.base_byte_offset
+						+ field_datum_byte_offset
+						+ obj_desc->common_field.access_byte_width)) {
+				return_ACPI_STATUS (AE_AML_REGION_LIMIT);
+			} else {
+				static int	warn_once = 1;
+				if (warn_once) {
+					// Could also associate a flag with each field, and
+					// warn once for each field.
+					ACPI_REPORT_WARNING((
+						"The ACPI AML in your computer contains errors, "
+						"please nag the manufacturer to correct it.\n"));
+					ACPI_REPORT_WARNING((
+						"Allowing relaxed access to fields; "
+						"turn on CONFIG_ACPI_DEBUG for details.\n"));
+					warn_once = 0;
+				}
+				return_ACPI_STATUS (AE_OK);
+			}
+		}
+		#else
+			return_ACPI_STATUS (AE_AML_REGION_LIMIT);
+		#endif
 	}
 
 	return_ACPI_STATUS (AE_OK);