[ACPI] Don't enable LAPIC when the BIOS disabled it.

Doing so apparently breaks every Dell on Earth.
http://bugzilla.kernel.org/show_bug.cgi?id=3238

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 8042a1472501e4a79c77c6b2a3b2c42917cef6de..2c647f98a4f48144e6e44e236f63e28763910cda 100644 (file)
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -690,22 +690,8 @@ static int __init detect_init_APIC (void)
                goto no_apic;
        }
 
-       if (!cpu_has_apic) {
-               /*
-                * Some BIOSes disable the local APIC in the
-                * APIC_BASE MSR. This can only be done in
-                * software for Intel P6 and AMD K7 (Model > 1).
-                */
-               rdmsr(MSR_IA32_APICBASE, l, h);
-               if (!(l & MSR_IA32_APICBASE_ENABLE)) {
-                       apic_printk(APIC_VERBOSE, "Local APIC disabled "
-                                       "by BIOS -- reenabling.\n");
-                       l &= ~MSR_IA32_APICBASE_BASE;
-                       l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
-                       wrmsr(MSR_IA32_APICBASE, l, h);
-                       enabled_via_apicbase = 1;
-               }
-       }
+       if (!cpu_has_apic)
+               goto no_apic;
        /*
         * The APIC feature bit should now be enabled
         * in `cpuid'