* [PATCH 2/2]cpuidle: makes AMD C1E works in suspend/resume path
@ 2009-05-19 8:09 Shaohua Li
2009-05-19 13:07 ` Thomas Gleixner
2009-05-27 3:45 ` Len Brown
0 siblings, 2 replies; 3+ messages in thread
From: Shaohua Li @ 2009-05-19 8:09 UTC (permalink / raw)
To: linux-kernel, linux-acpi; +Cc: mingo, thisistempbox, lenb
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>
---
drivers/acpi/processor_idle.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux/drivers/acpi/processor_idle.c
===================================================================
--- linux.orig/drivers/acpi/processor_idle.c 2009-05-19 09:56:59.000000000 +0800
+++ linux/drivers/acpi/processor_idle.c 2009-05-19 10:01:23.000000000 +0800
@@ -834,8 +834,8 @@ static int acpi_idle_enter_c1(struct cpu
/* Do not access any ACPI IO ports in suspend path */
if (acpi_idle_suspend) {
- acpi_safe_halt();
local_irq_enable();
+ cpu_relax();
return 0;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2]cpuidle: makes AMD C1E works in suspend/resume path
2009-05-19 8:09 [PATCH 2/2]cpuidle: makes AMD C1E works in suspend/resume path Shaohua Li
@ 2009-05-19 13:07 ` Thomas Gleixner
2009-05-27 3:45 ` Len Brown
1 sibling, 0 replies; 3+ messages in thread
From: Thomas Gleixner @ 2009-05-19 13:07 UTC (permalink / raw)
To: Shaohua Li; +Cc: linux-kernel, linux-acpi, mingo, thisistempbox, lenb
On Tue, 19 May 2009, Shaohua Li wrote:
> 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>
> ---
> drivers/acpi/processor_idle.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Index: linux/drivers/acpi/processor_idle.c
> ===================================================================
> --- linux.orig/drivers/acpi/processor_idle.c 2009-05-19 09:56:59.000000000 +0800
> +++ linux/drivers/acpi/processor_idle.c 2009-05-19 10:01:23.000000000 +0800
> @@ -834,8 +834,8 @@ static int acpi_idle_enter_c1(struct cpu
>
> /* Do not access any ACPI IO ports in suspend path */
> if (acpi_idle_suspend) {
> - acpi_safe_halt();
> local_irq_enable();
> + cpu_relax();
> return 0;
> }
Hmm, we removed the pm_idle_safe logic which took care of that in
older kernel versions :(
if (!cx || acpi_idle_suspend) {
if (pm_idle_save)
pm_idle_save();
else
acpi_safe_halt();
return;
}
That's what took care of the broadcast on those AMD C1E machines as
well.
But yeah, that cpu_relax() loop is probably fine for the suspend path.
Thanks,
tglx
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2]cpuidle: makes AMD C1E works in suspend/resume path
2009-05-19 8:09 [PATCH 2/2]cpuidle: makes AMD C1E works in suspend/resume path Shaohua Li
2009-05-19 13:07 ` Thomas Gleixner
@ 2009-05-27 3:45 ` Len Brown
1 sibling, 0 replies; 3+ messages in thread
From: Len Brown @ 2009-05-27 3:45 UTC (permalink / raw)
To: Shaohua Li; +Cc: linux-kernel, linux-acpi, mingo, thisistempbox
applied
thanks,
Len Brown, Intel Open Source Technology Center
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2009-05-27 3:46 UTC | newest]
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2009-05-19 13:07 ` Thomas Gleixner
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