Re: [PATCH] gpio: mvebu: convert to noirq suspend/resume to prevent interrupt storm on resume

[Bartosz Golaszewski]

On Wed, 8 Jul 2026 21:19:17 +0200, Rosen Penev <rosenp@xxxxxxxxx> said:
> On Wed, Jul 8, 2026 at 5:11 AM Bartosz Golaszewski <brgl@xxxxxxxxxx> wrote:
>>
>> On Wed, 8 Jul 2026 01:35:11 +0200, Rosen Penev <rosenp@xxxxxxxxx> said:
>> > The driver uses the legacy .suspend/.resume callbacks, but sets
>> > IRQCHIP_MASK_ON_SUSPEND on the irq_chip. During resume, the PM core
>> > runs dpm_resume_noirq() first, which calls irq_pm_resume() to unmask
>> > interrupts, and only then runs dpm_resume() which invokes the driver's
>> > .resume callback to restore GPIO registers (GPIO_IN_POL, GPIO_IO_CONF,
>> > mask registers).
>> >
>> > This ordering means interrupts are unmasked while the hardware is still
>> > in its reset state, potentially with incorrect polarities, causing
>> > spurious level-triggered interrupts before local IRQs are re-enabled.
>> >
>> > Convert the driver from legacy .suspend/.resume callbacks to noirq
>> > callbacks via dev_pm_ops. The noirq phase runs before resume_device_irqs()
>> > on resume and after suspend_device_irqs() on suspend, ensuring GPIO
>> > registers are restored before interrupts are unmasked.
>> >
>> > Assisted-by: opencode:big-pickle
>> > Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
>> > ---
>> >  drivers/gpio/gpio-mvebu.c | 15 +++++++++------
>> >  1 file changed, 9 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
>> > index a556fdb267a9..1df763e60726 100644
>> > --- a/drivers/gpio/gpio-mvebu.c
>> > +++ b/drivers/gpio/gpio-mvebu.c
>> > @@ -979,9 +979,9 @@ static const struct of_device_id mvebu_gpio_of_match[] = {
>> >       },
>> >  };
>> >
>> > -static int mvebu_gpio_suspend(struct platform_device *pdev, pm_message_t state)
>> > +static int mvebu_gpio_suspend(struct device *dev)
>>
>> Needs __maybe_unused for SET_NOIRQ_SYSTEM_SLEEP_PM_OPS().
> I see __maybe_unused and #ifdef for code like this. Which is prefered?

__maybe_unused is cleaner. Please add some newlines between quoted parts of
your emails and your responses for better readability. I'm finding myself
looking for where your response starts.

Bart