On Fri, Aug 01, 2025 at 04:29:43PM +0530, Krishna Chaitanya Chundru wrote:
> Some devices require more flexibility when configuring their dedicated
> wake-up interrupts, such as support for IRQF_SHARED or other IRQ flags.
I guess the "dedicated" in dev_pm_set_dedicated_wake_irq() means "an
interrupt that only signals wakeup requests, possibly used by several
devices," not "an interrupt only used by this device"?
> This is particularly useful in PCIe systems where multiple endpoints
> (e.g., Wi-Fi and Bluetooth controllers) share a common WAKE# signal
> line for waking the device from D3cold to D0. In such cases, drivers
> can use this API with IRQF_SHARED to register a shared wake IRQ handler.
Nit: WAKE# does not itself wakeup any devices. It only tells software
that the device *requested* a wakeup, and it's up to software to
actually perform it.
> 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);
> 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);
> +
> /**
> * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
> * @dev: Device
> diff --git a/include/linux/pm_wakeirq.h b/include/linux/pm_wakeirq.h
> index 25b63ed51b765c2c6919f259668a12675330835e..14950616efe34f4fa5408ca54cd8eeb1f7f0ff13 100644
> --- a/include/linux/pm_wakeirq.h
> +++ b/include/linux/pm_wakeirq.h
> @@ -11,6 +11,7 @@ extern int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq);
> extern int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq);
> extern void dev_pm_clear_wake_irq(struct device *dev);
> extern int devm_pm_set_wake_irq(struct device *dev, int irq);
> +extern int dev_pm_set_dedicated_wake_irq_flags(struct device *dev, int irq, unsigned long flags);
>
> #else /* !CONFIG_PM */
>
> @@ -38,5 +39,10 @@ static inline int devm_pm_set_wake_irq(struct device *dev, int irq)
> return 0;
> }
>
> +static inline int dev_pm_set_dedicated_wake_irq_flags(struct device *dev,
> + int irq, unsigned long flags)
> +{
> + return 0;
> +}
> #endif /* CONFIG_PM */
> #endif /* _LINUX_PM_WAKEIRQ_H */
>
> --
> 2.34.1
>
