Re: [PATCH v5 1/2] PM: sleep: wakeirq: Add support for custom IRQ flags in dedicated wake IRQ setup

[Krishna Chaitanya Chundru]

On 11/14/2025 10:20 PM, Rafael J. Wysocki wrote:
> On Fri, Nov 7, 2025 at 10:22 AM Krishna Chaitanya Chundru
> <krishna.chundru@xxxxxxxxxxxxxxxx> wrote:
> > Some devices require more flexibility when configuring their dedicated
> > wake-up interrupts, such as support for IRQF_SHARED or other IRQ flags.
> > This is particularly useful in PCIe systems where multiple endpoints
> > (e.g., Wi-Fi and Bluetooth controllers) share a common WAKE# signal
> > line which requests platform to re-establish power and reference clocks
> > to the components. In such cases, drivers can use this API with IRQF_SHARED
> > to register a shared wake IRQ handler.
> >
> > Update the internal helper __dev_pm_set_dedicated_wake_irq() to accept an
> > irq_flags argument. Modify the existing dev_pm_set_dedicated_wake_irq()
> > and dev_pm_set_dedicated_wake_irq_reverse() to preserve current behavior
> > by passing default flags (IRQF_ONESHOT | IRQF_NO_AUTOEN).
> >
> > Introduce a new API, dev_pm_set_dedicated_wake_irq_flags(), to allow
> > callers to specify custom IRQ flags. If IRQF_SHARED is used, remove
> > IRQF_NO_AUTOEN and disable the IRQ after setup to prevent spurious wakeups.
> >
> > Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/base/power/wakeirq.c | 43 ++++++++++++++++++++++++++++++++++++++-----
> >   include/linux/pm_wakeirq.h   |  6 ++++++
> >   2 files changed, 44 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
> > index 8aa28c08b2891f3af490175362cc1a759069bd50..655c28d5fc6850f50fc2ed74c5fbc066a21ae7b3 100644
> > --- a/drivers/base/power/wakeirq.c
> > +++ b/drivers/base/power/wakeirq.c
> > @@ -168,7 +168,8 @@ static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq)
> >          return IRQ_HANDLED;
> >   }
> >
> > -static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag)
> > +static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag,
> > +                                          unsigned int irq_flags)
> >   {
> >          struct wake_irq *wirq;
> >          int err;
> > @@ -197,8 +198,7 @@ static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned
> >           * so we use a threaded irq.
> >           */
> >          err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq,
> > -                                  IRQF_ONESHOT | IRQF_NO_AUTOEN,
> > -                                  wirq->name, wirq);
> > +                                  irq_flags, wirq->name, wirq);
> It looks like IRQF_ONESHOT will always be there in the flags, so maybe do
>
> +                                  IRQF_ONESHOT | irq_flags, wirq->name, wirq);
>
> here?
>
> >          if (err)
> >                  goto err_free_name;
> >
> > @@ -234,7 +234,7 @@ static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned
> >    */
> >   int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
> >   {
> > -       return __dev_pm_set_dedicated_wake_irq(dev, irq, 0);
> > +       return __dev_pm_set_dedicated_wake_irq(dev, irq, 0, IRQF_ONESHOT | IRQF_NO_AUTOEN);
> >   }
> >   EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
> >
> > @@ -255,10 +255,43 @@ EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
> >    */
> >   int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
> >   {
> > -       return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE);
> > +       return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE,
> > +                                              IRQF_ONESHOT | IRQF_NO_AUTOEN);
> >   }
> >   EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
> >
> > +/**
> > + * dev_pm_set_dedicated_wake_irq_flags - Request a dedicated wake-up interrupt
> > + *                                       with custom flags
> > + * @dev: Device entry
> > + * @irq: Device wake-up interrupt
> > + * @flags: IRQ flags (e.g., IRQF_SHARED)
> > + *
> > + * This API sets up a threaded interrupt handler for a device that has
> > + * a dedicated wake-up interrupt in addition to the device IO interrupt,
> > + * allowing the caller to specify custom IRQ flags such as IRQF_SHARED.
> > + *
> > + * Returns 0 on success or a negative error code on failure.
> > + */
> > +int dev_pm_set_dedicated_wake_irq_flags(struct device *dev, int irq, unsigned long flags)
> > +{
> > +       struct wake_irq *wirq;
> > +       int ret;
> > +
> > +       flags |= IRQF_ONESHOT;
> > +       if (!(flags & IRQF_SHARED))
> > +               flags |= IRQF_NO_AUTOEN;
> > +
> > +       ret =  __dev_pm_set_dedicated_wake_irq(dev, irq, 0, flags);
> > +       if (!ret && (flags & IRQF_SHARED)) {
> > +               wirq = dev->power.wakeirq;
> > +               disable_irq_nosync(wirq->irq);
> > +       }
> > +
> > +       return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_flags);
> Instead of this, I'd introduce
>
> int dev_pm_set_dedicated_shared_wake_irq(struct device *dev, int irq,
> unsigned long additional_flags)
>
> that would pass IRQF_SHARED combined with additional_flags to
> __dev_pm_set_dedicated_wake_irq() to avoid having two different helper
> functions that can be used for the same purpose.
>
> I think that it would be sufficient for your use case.
Ack.

- Krishna Chaitanya.