Add patch to fix regression in FADT revision checks (rhbz 730007 727865)

1 files changed, 58 insertions, 0 deletions

diff --git a/ACPICA-Fix-regression-in-FADT-revision-checks.patch b/ACPICA-Fix-regression-in-FADT-revision-checks.patch
new file mode 100644
index 000000000..d6b590389
--- /dev/null
+++ b/ACPICA-Fix-regression-in-FADT-revision-checks.patch
@@ -0,0 +1,58 @@
+	commit 64b3db22c04586997ab4be46dd5a5b99f8a2d390 (2.6.39),
+"Remove use of unreliable FADT revision field" causes regression
+for old P4 systems because now cst_control and other fields are
+not reset to 0.
+
+	The effect is that acpi_processor_power_init will notice
+cst_control != 0 and a write to CST_CNT register is performed
+that should not happen. As result, the system oopses after the
+"No _CST, giving up" message, sometimes in acpi_ns_internalize_name,
+sometimes in acpi_ns_get_type, usually at random places. May be
+during migration to CPU 1 in acpi_processor_get_throttling.
+
+	Every one of these settings help to avoid this problem:
+ - acpi=off
+ - processor.nocst=1
+ - maxcpus=1
+
+	The fix is to update acpi_gbl_FADT.header.length after
+the original value is used to check for old revisions.
+
+Signed-off-by: Julian Anastasov <ja@ssi.bg>
+---
+ drivers/acpi/acpica/tbfadt.c |    8 ++++----
+ 1 files changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c
+index c5d8704..4c9c760 100644
+--- a/drivers/acpi/acpica/tbfadt.c
++++ b/drivers/acpi/acpica/tbfadt.c
+@@ -363,10 +363,6 @@ static void acpi_tb_convert_fadt(void)
+ 	u32 address32;
+ 	u32 i;
+ 
+-	/* Update the local FADT table header length */
+-
+-	acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
+-
+ 	/*
+ 	 * Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary.
+ 	 * Later code will always use the X 64-bit field. Also, check for an
+@@ -408,6 +404,10 @@ static void acpi_tb_convert_fadt(void)
+ 		acpi_gbl_FADT.boot_flags = 0;
+ 	}
+ 
++	/* Update the local FADT table header length */
++
++	acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
++
+ 	/*
+ 	 * Expand the ACPI 1.0 32-bit addresses to the ACPI 2.0 64-bit "X"
+ 	 * generic address structures as necessary. Later code will always use
+-- 
+1.7.3.4
+
+--
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