From: Shaohua Li <shaohua.li@intel.com>
Date: Tue, 19 May 2009 08:09:54 +0000 (+0800)
Subject: cpuidle: fix AMD C1E suspend hang
X-Git-Tag: v2.6.30-rc8~13^2^2
X-Git-Url: http://bbs.cooldavid.org/git/?a=commitdiff_plain;h=7d60e8ab0d5507229dfbdf456501cc378610fa01;p=net-next-2.6.git

cpuidle: fix AMD C1E suspend hang

When AMD C1E is enabled, local APIC timer will stop even in C1. To avoid
suspend/resume hang, this patch removes C1 and replace it with a cpu_relax() in
suspend/resume path. This hasn't any impact in runtime path.

http://bugzilla.kernel.org/show_bug.cgi?id=13233

[ impact: avoid suspend/resume hang in AMD CPU with C1E enabled ]

Tested-by: Dmitry Lyzhyn <thisistempbox@yahoo.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
---

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 6b7bcc7e3e1..10a2d913635 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -834,8 +834,8 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 
 	/* Do not access any ACPI IO ports in suspend path */
 	if (acpi_idle_suspend) {
-		acpi_safe_halt();
 		local_irq_enable();
+		cpu_relax();
 		return 0;
 	}