From: Ingo Molnar <mingo@elte.hu>
Date: Thu, 22 Mar 2007 09:31:19 +0000 (+0100)
Subject: [PATCH] setup_boot_APIC_clock() irq-enable fix
X-Git-Tag: v2.6.21-rc5~32
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4edc5db83f574dfcc8be35b7b96760ded543b360;p=linux-2.6

[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 3682511783..244c3fe9b8 100644
--- 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