diff mbox series

PM: wakeirq: fix wake irq warning in system suspend stage

Message ID 20240228020040.25815-1-qingliang.li@mediatek.com
State Superseded
Headers show
Series PM: wakeirq: fix wake irq warning in system suspend stage | expand

Commit Message

Qingliang Li Feb. 28, 2024, 2 a.m. UTC
When driver registers the wake irq with reverse enable ordering,
the wake irq will be re-enabled when entering system suspend, triggering
an 'Unbalanced enable for IRQ xxx' warning. The wake irq will be
enabled in both dev_pm_enable_wake_irq_complete() and dev_pm_arm_wake_irq()

To fix this issue, complete the setting of WAKE_IRQ_DEDICATED_ENABLED flag
in dev_pm_enable_wake_irq_complete() to avoid redundant irq enablement.

Fixes: 8527beb12087 ("PM: sleep: wakeirq: fix wake irq arming")
Signed-off-by: Qingliang Li <qingliang.li@mediatek.com>
---
 drivers/base/power/wakeirq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Dhruva Gole Feb. 28, 2024, 6:04 a.m. UTC | #1
Hi,

On 28/02/24 07:30, Qingliang Li wrote:
> When driver registers the wake irq with reverse enable ordering,
> the wake irq will be re-enabled when entering system suspend, triggering
> an 'Unbalanced enable for IRQ xxx' warning. The wake irq will be
> enabled in both dev_pm_enable_wake_irq_complete() and dev_pm_arm_wake_irq()
> 
> To fix this issue, complete the setting of WAKE_IRQ_DEDICATED_ENABLED flag
> in dev_pm_enable_wake_irq_complete() to avoid redundant irq enablement.


Just trying to understand, why not in dev_pm_arm_wake_irq ?
Is it cuz it's called much after dev_pm_enable_wake_irq_complete ?
Not sure what's the exact call order, but I am assuming
dev_pm_enable_wake_irq_complete is more of a runtime thing and
dev_pm_arm_wake_irq happens finally at system suspend?

> 
> Fixes: 8527beb12087 ("PM: sleep: wakeirq: fix wake irq arming")
> Signed-off-by: Qingliang Li <qingliang.li@mediatek.com>
> ---

$subject: Most recent convention used for this file is:
"PM: sleep: wakeirq:  ..."

>   drivers/base/power/wakeirq.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
> index 42171f766dcb..5a5a9e978e85 100644
> --- a/drivers/base/power/wakeirq.c
> +++ b/drivers/base/power/wakeirq.c
> @@ -313,8 +313,10 @@ void dev_pm_enable_wake_irq_complete(struct device *dev)
>   		return;
>   
>   	if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
> -	    wirq->status & WAKE_IRQ_DEDICATED_REVERSE)
> +	    wirq->status & WAKE_IRQ_DEDICATED_REVERSE) {
>   		enable_irq(wirq->irq);
> +		wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
> +	}

But this does make sense to make sure status is updated,
You can pick my R-by.

Reviewed-by: Dhruva Gole <d-gole@ti.com>
Dhruva Gole Feb. 28, 2024, 8:58 a.m. UTC | #2
Hello,

On 28/02/24 14:03, Qingliang Li (黎晴亮) wrote:
> On Wed, 2024-02-28 at 11:34 +0530, Dhruva Gole wrote:
>>   	
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>   Hi,
>>
>> On 28/02/24 07:30, Qingliang Li wrote:
>>> When driver registers the wake irq with reverse enable ordering,
>>> the wake irq will be re-enabled when entering system suspend,
>> triggering
>>> an 'Unbalanced enable for IRQ xxx' warning. The wake irq will be
>>> enabled in both dev_pm_enable_wake_irq_complete() and
>> dev_pm_arm_wake_irq()
>>>
>>> To fix this issue, complete the setting of
>> WAKE_IRQ_DEDICATED_ENABLED flag
>>> in dev_pm_enable_wake_irq_complete() to avoid redundant irq
>> enablement.
>>
>>
>> Just trying to understand, why not in dev_pm_arm_wake_irq ?
>> Is it cuz it's called much after dev_pm_enable_wake_irq_complete ?
>> Not sure what's the exact call order, but I am assuming
>> dev_pm_enable_wake_irq_complete is more of a runtime thing and
>> dev_pm_arm_wake_irq happens finally at system suspend?
> 
> You are right, the involvement of 'dev_pm_enable_wake_irq_complete' is
> due to the driver selecting 'pm_runtime_force_suspend' as the callback
> function for system suspend. In this scenario, the call sequence during
> system suspend is as follows:
> dpm_suspend_start -> dpm_run_callback -> pm_runtime_force_suspend ->
> dev_pm_enable_wake_irq_check/complete
> suspend_enter -> dpm_suspend_noirq -> dev_pm_arm_wake_irq

OK this is what I expected, thanks for clarifying!

> 
> Based on the above, if the driver (i) chooses pm_runtime_force_suspend
> as the system suspend callback function and (ii) registers wake irq
> with reverse enable ordering, the wake irq will be enabled twice during
> system suspend.

Yep, makes sense

> 
>>
>>>
>>> Fixes: 8527beb12087 ("PM: sleep: wakeirq: fix wake irq arming")
>>> Signed-off-by: Qingliang Li <qingliang.li@mediatek.com>
>>> ---
>>
>> $subject: Most recent convention used for this file is:
>> "PM: sleep: wakeirq:  ..."
> 
> I'm sorry, but what is the problem with the description of the "Fixed"
> field? I didn't get your point and I wrote it according to the previous
> patches.

I am not talking about your "Fixed", I am taking about the subject line
of the patch.
You've used "PM: wakeirq: fix wake ..."

Instead use
"PM: sleep: wakeirq: fix wake ..."

No strong objections here, it's just a nit.

[..snip..]
Rafael J. Wysocki Feb. 29, 2024, 7:31 p.m. UTC | #3
On Wed, Feb 28, 2024 at 9:33 AM Qingliang Li (黎晴亮)
<Qingliang.Li@mediatek.com> wrote:
>
> On Wed, 2024-02-28 at 11:34 +0530, Dhruva Gole wrote:
> >
> > External email : Please do not click links or open attachments until
> > you have verified the sender or the content.
> >  Hi,
> >
> > On 28/02/24 07:30, Qingliang Li wrote:
> > > When driver registers the wake irq with reverse enable ordering,
> > > the wake irq will be re-enabled when entering system suspend,
> > triggering
> > > an 'Unbalanced enable for IRQ xxx' warning. The wake irq will be
> > > enabled in both dev_pm_enable_wake_irq_complete() and
> > dev_pm_arm_wake_irq()
> > >
> > > To fix this issue, complete the setting of
> > WAKE_IRQ_DEDICATED_ENABLED flag
> > > in dev_pm_enable_wake_irq_complete() to avoid redundant irq
> > enablement.
> >
> >
> > Just trying to understand, why not in dev_pm_arm_wake_irq ?
> > Is it cuz it's called much after dev_pm_enable_wake_irq_complete ?
> > Not sure what's the exact call order, but I am assuming
> > dev_pm_enable_wake_irq_complete is more of a runtime thing and
> > dev_pm_arm_wake_irq happens finally at system suspend?
>
> You are right, the involvement of 'dev_pm_enable_wake_irq_complete' is
> due to the driver selecting 'pm_runtime_force_suspend' as the callback
> function for system suspend. In this scenario, the call sequence during
> system suspend is as follows:
> dpm_suspend_start -> dpm_run_callback -> pm_runtime_force_suspend ->
> dev_pm_enable_wake_irq_check/complete
> suspend_enter -> dpm_suspend_noirq -> dev_pm_arm_wake_irq
>
> Based on the above, if the driver (i) chooses pm_runtime_force_suspend
> as the system suspend callback function and (ii) registers wake irq
> with reverse enable ordering, the wake irq will be enabled twice during
> system suspend.

It would be good to put the above information into the patch
changelog, as it actually explains the problem.

Thanks!
diff mbox series

Patch

diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
index 42171f766dcb..5a5a9e978e85 100644
--- a/drivers/base/power/wakeirq.c
+++ b/drivers/base/power/wakeirq.c
@@ -313,8 +313,10 @@  void dev_pm_enable_wake_irq_complete(struct device *dev)
 		return;
 
 	if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
-	    wirq->status & WAKE_IRQ_DEDICATED_REVERSE)
+	    wirq->status & WAKE_IRQ_DEDICATED_REVERSE) {
 		enable_irq(wirq->irq);
+		wirq->status |= WAKE_IRQ_DEDICATED_ENABLED;
+	}
 }
 
 /**