Re: [PATCH] PM: wakeirq: fix wake irq warning in system suspend stage

[Dhruva Gole]

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@xxxxxxxxxxxx>
> > > ---
> >
> > $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..]

--
Thanks and Regards,
Dhruva Gole