1 files changed, 11 insertions, 0 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 4c51a2f8fd31..de8ce79dd881 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;