x86: keep MP_intsrc_info untouched if we do not update mptable
Daniel Exner reported IO-APIC enumeration breakage in linux-next.
Alexey Starikovskiy found out that it might be related to
commit 2944e16b25 "x86: update mptable".
use enable_update_mptable to decide if need check before add mp_irqs array.
Reported-by: Daniel Exner <webmaster@dragonslave.de>
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index caf4ed7..4d370b1 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1172,6 +1172,9 @@
struct mpc_config_intsrc intsrc;
int ioapic;
+ if (!enable_update_mptable)
+ return 0;
+
/* print the entry should happen on mptable identically */
intsrc.mpc_type = MP_INTSRC;
intsrc.mpc_irqtype = mp_INT;
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index b62ac6b..014ac5d 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -34,6 +34,8 @@
#include <mach_mpparse.h>
#endif
+int enable_update_mptable;
+
/*
* Checksum an MP configuration block.
*/
@@ -295,10 +297,11 @@
print_MP_intsrc_info(m);
- for (i = 0; i < mp_irq_entries; i++) {
- if (!mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m))
- return;
- }
+ if (enable_update_mptable)
+ for (i = 0; i < mp_irq_entries; i++) {
+ if (!mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m))
+ return;
+ }
assign_to_mp_irq(m, &mp_irqs[mp_irq_entries]);
if (++mp_irq_entries == MAX_IRQ_SOURCES)
@@ -1110,8 +1113,6 @@
return 0;
}
-int __initdata enable_update_mptable;
-
static int __init update_mptable_setup(char *str)
{
enable_update_mptable = 1;