ACPI: fix boot hang w/o "noapic" on MSI MS-6390-L
This is a workaround to handle a BIOS bug where the
programmer exchanged the name and index fields of
a _PRT entry. Apparently this BIOS error does not
confuse Windows and thus it lurks in the field
on various machines.
boot with "acpi=strict" to disable this workaround
http://bugzilla.kernel.org/show_bug.cgi?id=6859
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/resources/rscreate.c b/drivers/acpi/resources/rscreate.c
index 1358c06..cc48ab0 100644
--- a/drivers/acpi/resources/rscreate.c
+++ b/drivers/acpi/resources/rscreate.c
@@ -191,6 +191,9 @@
user_prt = ACPI_CAST_PTR(struct acpi_pci_routing_table, buffer);
for (index = 0; index < number_of_elements; index++) {
+ int source_name_index = 2;
+ int source_index_index = 3;
+
/*
* Point user_prt past this current structure
*
@@ -261,10 +264,28 @@
}
/*
+ * If BIOS erroneously reversed the _PRT source_name and source_index,
+ * then reverse them back.
+ */
+ if (ACPI_GET_OBJECT_TYPE (sub_object_list[3]) != ACPI_TYPE_INTEGER) {
+ if (acpi_gbl_enable_interpreter_slack) {
+ source_name_index = 3;
+ source_index_index = 2;
+ printk(KERN_WARNING "ACPI: Handling Garbled _PRT entry\n");
+ } else {
+ ACPI_ERROR((AE_INFO,
+ "(PRT[%X].source_index) Need Integer, found %s",
+ index,
+ acpi_ut_get_object_type_name(sub_object_list[3])));
+ return_ACPI_STATUS(AE_BAD_DATA);
+ }
+ }
+
+ /*
* 3) Third subobject: Dereference the PRT.source_name
* The name may be unresolved (slack mode), so allow a null object
*/
- obj_desc = sub_object_list[2];
+ obj_desc = sub_object_list[source_name_index];
if (obj_desc) {
switch (ACPI_GET_OBJECT_TYPE(obj_desc)) {
case ACPI_TYPE_LOCAL_REFERENCE:
@@ -339,7 +360,7 @@
/* 4) Fourth subobject: Dereference the PRT.source_index */
- obj_desc = sub_object_list[3];
+ obj_desc = sub_object_list[source_index_index];
if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_INTEGER) {
user_prt->source_index = (u32) obj_desc->integer.value;
} else {