On 03/23/2016 05:38 PM, santosh shilimkar wrote:
> Hi,
>
> On 3/23/2016 8:07 AM, Tony Lindgren wrote:
>> Hi,
>>
>> * Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx> [160323 02:28]:
>>>
>>> the hotplug notifier in arch/arm/mach-omap2/omap-wakeupgen.c doesn't
>>> handle the corresponding FROZEN transitions. Is there a reason for it?
>>
> FROZEN event as such doesn't matter from wakeupgen and its context
> point of view since CPU(s) and its power domain are still alive.
>
>> Adding Santosh to Cc too.
>>
>> I don't think it's needed in this case as omap-wakeupgen.c just
>> basically takes care of the context save before powering off and
>> context restore right after power on. It's only a helper for the
>> bootrom code. The FROZEN transitions are handled at a higher
>> level by drivers/cpuidle/coupled.c.
>>
>> Or maybe I'm missing something, if so please let me know :)
>>
> You are correct Tony.
Hm. I'm not sure. I assume this question is about CPU_TASKS_FROZEN. Right?
if yes the irq_cpu_hotplug_notify() can be called from two code paths now
1) cpu hotplug
cpu_down()/cpu_up()
... -> irq_cpu_hotplug_notify() and CPU_TASKS_FROZEN is *not* set
action = [CPU_ONLINE:CPU_DEAD]
and wakeupgen_irqmask_all() will be executed
2) suspend & friends
disable_nonboot_cpus()/enable_nonboot_cpus()
... -> irq_cpu_hotplug_notify() and CPU_TASKS_FROZEN is set
action = [CPU_ONLINE_FROZEN:CPU_DEAD_FROZEN]
and wakeupgen_irqmask_all() will *not* be executed
In case 2 wakeupgen IRQs will not be masked for non-boot CPU before entering Suspend
Not sure how critical it is, but think below diff could be right thing to do:
iff --git a/arch/arm/mach-omap2/omap-wakeupgen.c b/arch/arm/mach-omap2/omap-wakeupgen.c
index f397bd6..b28c504 100644
--- a/arch/arm/mach-omap2/omap-wakeupgen.c
+++ b/arch/arm/mach-omap2/omap-wakeupgen.c
@@ -320,7 +320,7 @@ static int irq_cpu_hotplug_notify(struct notifier_block *self,
{
unsigned int cpu = (unsigned int)hcpu;
- switch (action) {
+ switch (action & ~CPU_TASKS_FROZEN) {
case CPU_ONLINE:
wakeupgen_irqmask_all(cpu, 0);
break;
--
regards,
-grygorii
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