From: Julian Anastasov <ja@xxxxxx> 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. https://bugzilla.kernel.org/show_bug.cgi?id=42700 https://bugzilla.redhat.com/show_bug.cgi?id=727865 Signed-off-by: Julian Anastasov <ja@xxxxxx> Acked-by: Bob Moore <robert.moore@xxxxxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- drivers/acpi/acpica/tbfadt.c | 8 ++++---- 1 file 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 -- 1.7.10.rc2.19.gfae9d -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
