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authorLen Brown <len.brown@intel.com>2008-12-23 01:47:42 -0500
committerLen Brown <len.brown@intel.com>2008-12-23 01:47:42 -0500
commit7b37b5fd9ba32c0c5afc3537eed7e7466f2173e2 (patch)
treeb90d287473c7a1d7e23981d13287523e219d6e5a
parent3d44cc3e01ee1b40317f79ed54324e25c4f848df (diff)
ACPI: disable MPS when NO APIC-table found
When ACPI is asked to find an MADT (APIC table) and fails, then ACPI expects to run in PIC mode. However, if an MP Table is was found, IRQs will be registered as if an IOAPIC is being used, even though ACPI is configuring interrupt links links for PIC mode. In this scenario, disable MPS so that IRQs are registered in PIC mode, consistent with ACPI. http://bugzilla.kernel.org/show_bug.cgi?id=12257 Signed-off-by: Len Brown <len.brown@intel.com>
-rw-r--r--arch/x86/kernel/acpi/boot.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 4c51a2f8fd3..de8ce79dd88 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1359,6 +1359,17 @@ static void __init acpi_process_madt(void)
"Invalid BIOS MADT, disabling ACPI\n");
disable_acpi();
}
+ } else {
+ /*
+ * ACPI found no MADT, and so ACPI wants UP PIC mode.
+ * In the event an MPS table was found, forget it.
+ * Boot with "acpi=off" to use MPS on such a system.
+ */
+ if (smp_found_config) {
+ printk(KERN_WARNING PREFIX
+ "No APIC-table, disabling MPS\n");
+ smp_found_config = 0;
+ }
}
#endif
return;