[PATCH] x86, reboot: skip reboot_fixups in early boot phase

[Joonsoo Kim <js1304@gmail.com>]

During early boot phase, PCI bus subsystem is not yet initialized.
If panic is occured in early boot phase and panic_timeout is set,
code flow go into emergency_restart() and hit mach_reboot_fixups(), then
encounter another panic. When second panic, we can't hold a panic_lock, so
code flow go into panic_smp_self_stop() which prevent system to restart.

For avoid second panic, skip reboot_fixups in early boot phase.
It makes panic_timeout works in early boot phase.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Joonsoo Kim <js1304@gmail.com>

diff --git a/arch/x86/kernel/reboot_fixups_32.c b/arch/x86/kernel/reboot_fixups_32.c
index c8e41e9..b9b8ec9 100644
--- a/arch/x86/kernel/reboot_fixups_32.c
+++ b/arch/x86/kernel/reboot_fixups_32.c
@@ -89,6 +89,10 @@ void mach_reboot_fixups(void)
 	if (in_interrupt())
 		return;
 
+	/* During early boot phase, PCI is not yet initialized */
+	if (system_state == SYSTEM_BOOTING)
+		return;
+
 	for (i=0; i < ARRAY_SIZE(fixups_table); i++) {
 		cur = &(fixups_table[i]);
 		dev = pci_get_device(cur->vendor, cur->device, NULL);
-- 
1.7.9.5