cpuidle: fix AMD C1E suspend hang

commit 7d60e8ab0d5507229dfbdf456501cc378610fa01 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 1a56bfb441402578f7a3b445b61b50b67c12aa61..61f6b7abea48aebd8a49de59de32d0c265fd587b 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -870,8 +870,8 @@ 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;
        }