[PATCH] setup_boot_APIC_clock() irq-enable fix

latest -git triggers an irqtrace/lockdep warning of a leaked
irqs-off condition:

  BUG: at kernel/fork.c:1033 copy_process()

after some debugging it turns out that commit ca1b940c accidentally left
interrupts disabled - which trickled down all the way to the first time
we fork a kernel thread and triggered the warning.

the fix is to re-enable interrupts in the 'else' branch of
setup_boot_APIC_clock()'s pmtimers calibration path.

Reported-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@brown.paperbag.linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 36825117835d5ede88c4dc992457d064374ad07e..244c3fe9b8c3acc754d79f51eac28a9ee456d93f 100644 (file)
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -506,7 +506,8 @@ void __init setup_boot_APIC_clock(void)
                        apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
                else
                        local_apic_timer_verify_ok = 0;
-       }
+       } else
+               local_irq_enable();
 
        if (!local_apic_timer_verify_ok) {
                printk(KERN_WARNING