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Message-ID: <CAJZ5v0gb6vN9kHeQbgjRQXvOCNaFK8ur7bLDeAVjDqdT2=a+-g@mail.gmail.com>
Date: Tue, 26 Oct 2021 17:39:53 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Chunfeng Yun <chunfeng.yun@...iatek.com>
Cc: "Rafael J . Wysocki" <rafael@...nel.org>,
Len Brown <len.brown@...el.com>, Pavel Machek <pavel@....cz>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Mathias Nyman <mathias.nyman@...el.com>,
Matthias Brugger <matthias.bgg@...il.com>,
Linux PM <linux-pm@...r.kernel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
"open list:ULTRA-WIDEBAND (UWB) SUBSYSTEM:"
<linux-usb@...r.kernel.org>,
Linux ARM <linux-arm-kernel@...ts.infradead.org>,
"moderated list:ARM/Mediatek SoC..."
<linux-mediatek@...ts.infradead.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>
Subject: Re: [PATCH v4 1/3] PM / wakeirq: support enabling wake-up irq after
runtime_suspend called
On Mon, Oct 25, 2021 at 9:02 AM Chunfeng Yun <chunfeng.yun@...iatek.com> wrote:
>
> When the dedicated wake IRQ is level trigger, and it uses the
> device's low-power status as the wakeup source, that means if the
> device is not in low-power state, the wake IRQ will be triggered
> if enabled; For this case, need enable the wake IRQ after running
> the device's ->runtime_suspend() which make it enter low-power state.
>
> e.g.
> Assume the wake IRQ is a low level trigger type, and the wakeup
> signal comes from the low-power status of the device.
> The wakeup signal is low level at running time (0), and becomes
> high level when the device enters low-power state (runtime_suspend
> (1) is called), a wakeup event at (2) make the device exit low-power
> state, then the wakeup signal also becomes low level.
>
> ------------------
> | ^ ^|
> ---------------- | | --------------
> |<---(0)--->|<--(1)--| (3) (2) (4)
>
> if enable the wake IRQ before running runtime_suspend during (0),
> a wake IRQ will arise, it causes resume immediately;
> it works if enable wake IRQ ( e.g. at (3) or (4)) after running
> ->runtime_suspend().
>
> This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
> optionally support enabling wake IRQ after running ->runtime_suspend().
>
> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@...iatek.com>
I don't really have anything to add regarding the code.
The kerneldoc comments could be improved, but I can take care of this
when applying the patch.
Please collect ACKs for the remaining 2 patches in the series and I
will pick up all three.
Thanks!
> ---
> v4: changes according to Rafael's suggestions
> 1. rename new flag as WAKE_IRQ_DEDICATED_REVERSE;
> 2. add __dev_pm_set_dedicated_wake_irq() with flag parameter, then
> rebuild dev_pm_set_dedicated_wake_irq() and add new api
> dev_pm_set_dedicated_wake_irq_reverse();
> 3. rename the new added parameter as cond_disable in
> dev_pm_disable_wake_irq_check(), and also simplify its flow;
> 4. modify some comments
>
> v3: add new status suggested by Rafael
>
> v2: add more commit message
>
> Use the falling edge trigger interrupt suggested by Ikjoon [1], it
> works well at firstly when only use this related wakeup source, but
> encounter issues if use other wakeup sources to wakeup platform as
> below steps:
> 1. use another wakeup source to wake up the suspended system;
> 2. the consumer's resume() will be called, and exits sleep state;
> 3. the consumer's wakeup signal will fall into low level, due to
> currently the wakeup irq is disabled, the wake-irq is pending;
> 4. the consumer tries to enter runtime suspend, but there is a
> pending wakeup irq, so will resume again, this will repeat
> endlessly.
>
> Send out the patch again for further discussion.
>
> [1]: https://patchwork.kernel.org/patch/12190407
>
> ---
> drivers/base/power/power.h | 7 ++-
> drivers/base/power/runtime.c | 6 ++-
> drivers/base/power/wakeirq.c | 101 +++++++++++++++++++++++++++--------
> include/linux/pm_wakeirq.h | 9 +++-
> 4 files changed, 96 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
> index 54292cdd7808..0eb7f02b3ad5 100644
> --- a/drivers/base/power/power.h
> +++ b/drivers/base/power/power.h
> @@ -25,8 +25,10 @@ extern u64 pm_runtime_active_time(struct device *dev);
>
> #define WAKE_IRQ_DEDICATED_ALLOCATED BIT(0)
> #define WAKE_IRQ_DEDICATED_MANAGED BIT(1)
> +#define WAKE_IRQ_DEDICATED_REVERSE BIT(2)
> #define WAKE_IRQ_DEDICATED_MASK (WAKE_IRQ_DEDICATED_ALLOCATED | \
> - WAKE_IRQ_DEDICATED_MANAGED)
> + WAKE_IRQ_DEDICATED_MANAGED | \
> + WAKE_IRQ_DEDICATED_REVERSE)
>
> struct wake_irq {
> struct device *dev;
> @@ -39,7 +41,8 @@ extern void dev_pm_arm_wake_irq(struct wake_irq *wirq);
> extern void dev_pm_disarm_wake_irq(struct wake_irq *wirq);
> extern void dev_pm_enable_wake_irq_check(struct device *dev,
> bool can_change_status);
> -extern void dev_pm_disable_wake_irq_check(struct device *dev);
> +extern void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable);
> +extern void dev_pm_enable_wake_irq_complete(struct device *dev);
>
> #ifdef CONFIG_PM_SLEEP
>
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index ec94049442b9..d504cd4ab3cb 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -645,6 +645,8 @@ static int rpm_suspend(struct device *dev, int rpmflags)
> if (retval)
> goto fail;
>
> + dev_pm_enable_wake_irq_complete(dev);
> +
> no_callback:
> __update_runtime_status(dev, RPM_SUSPENDED);
> pm_runtime_deactivate_timer(dev);
> @@ -690,7 +692,7 @@ static int rpm_suspend(struct device *dev, int rpmflags)
> return retval;
>
> fail:
> - dev_pm_disable_wake_irq_check(dev);
> + dev_pm_disable_wake_irq_check(dev, true);
> __update_runtime_status(dev, RPM_ACTIVE);
> dev->power.deferred_resume = false;
> wake_up_all(&dev->power.wait_queue);
> @@ -873,7 +875,7 @@ static int rpm_resume(struct device *dev, int rpmflags)
>
> callback = RPM_GET_CALLBACK(dev, runtime_resume);
>
> - dev_pm_disable_wake_irq_check(dev);
> + dev_pm_disable_wake_irq_check(dev, false);
> retval = rpm_callback(callback, dev);
> if (retval) {
> __update_runtime_status(dev, RPM_SUSPENDED);
> diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
> index b91a3a9bf9f6..76c163a89104 100644
> --- a/drivers/base/power/wakeirq.c
> +++ b/drivers/base/power/wakeirq.c
> @@ -142,24 +142,7 @@ static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq)
> return IRQ_HANDLED;
> }
>
> -/**
> - * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
> - * @dev: Device entry
> - * @irq: Device wake-up interrupt
> - *
> - * Unless your hardware has separate wake-up interrupts in addition
> - * to the device IO interrupts, you don't need this.
> - *
> - * Sets up a threaded interrupt handler for a device that has
> - * a dedicated wake-up interrupt in addition to the device IO
> - * interrupt.
> - *
> - * The interrupt starts disabled, and needs to be managed for
> - * the device by the bus code or the device driver using
> - * dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq()
> - * functions.
> - */
> -int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
> +static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag)
> {
> struct wake_irq *wirq;
> int err;
> @@ -197,7 +180,7 @@ int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
> if (err)
> goto err_free_irq;
>
> - wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED;
> + wirq->status = WAKE_IRQ_DEDICATED_ALLOCATED | flag;
>
> return err;
>
> @@ -210,8 +193,57 @@ int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
>
> return err;
> }
> +
> +
> +/**
> + * dev_pm_set_dedicated_wake_irq - Request a dedicated wake-up interrupt
> + * @dev: Device entry
> + * @irq: Device wake-up interrupt
> + *
> + * Unless your hardware has separate wake-up interrupts in addition
> + * to the device IO interrupts, you don't need this.
> + *
> + * Sets up a threaded interrupt handler for a device that has
> + * a dedicated wake-up interrupt in addition to the device IO
> + * interrupt.
> + *
> + * The interrupt starts disabled, and needs to be managed for
> + * the device by the bus code or the device driver using
> + * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*()
> + * functions.
> + */
> +int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
> +{
> + return __dev_pm_set_dedicated_wake_irq(dev, irq, 0);
> +}
> EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
>
> +/**
> + * dev_pm_set_dedicated_wake_irq_reverse - Request a dedicated wake-up interrupt
> + * with setting flag WAKE_IRQ_DEDICATED_REVERSE
> + * @dev: Device entry
> + * @irq: Device wake-up interrupt
> + *
> + * Unless your hardware has separate wake-up interrupts in addition
> + * to the device IO interrupts, you don't need this.
> + *
> + * Sets up a threaded interrupt handler for a device that has a dedicated
> + * wake-up interrupt in addition to the device IO interrupt. It sets
> + * the status of WAKE_IRQ_DEDICATED_REVERSE to tell rpm_suspend()
> + * to enable dedicated wake-up interrupt after running the
> + * ->runtime_suspend()
> + *
> + * The interrupt starts disabled, and needs to be managed for
> + * the device by the bus code or the device driver using
> + * dev_pm_enable_wake_irq*() and dev_pm_disable_wake_irq*()
> + * functions.
> + */
> +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);
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
> +
> /**
> * dev_pm_enable_wake_irq - Enable device wake-up interrupt
> * @dev: Device
> @@ -282,27 +314,54 @@ void dev_pm_enable_wake_irq_check(struct device *dev,
> return;
>
> enable:
> - enable_irq(wirq->irq);
> + if (!can_change_status || !(wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
> + enable_irq(wirq->irq);
> }
>
> /**
> * dev_pm_disable_wake_irq_check - Checks and disables wake-up interrupt
> * @dev: Device
> + * @cond_disable: if set, also check WAKE_IRQ_DEDICATED_REVERSE
> *
> * Disables wake-up interrupt conditionally based on status.
> * Should be only called from rpm_suspend() and rpm_resume() path.
> */
> -void dev_pm_disable_wake_irq_check(struct device *dev)
> +void dev_pm_disable_wake_irq_check(struct device *dev, bool cond_disable)
> {
> struct wake_irq *wirq = dev->power.wakeirq;
>
> if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
> return;
>
> + if (cond_disable && (wirq->status & WAKE_IRQ_DEDICATED_REVERSE))
> + return;
> +
> if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED)
> disable_irq_nosync(wirq->irq);
> }
>
> +/**
> + * dev_pm_enable_wake_irq_complete - enable wake IRQ not enabled before
> + * @dev: Device using the wake IRQ
> + *
> + * Enable wake IRQ conditionally based on status, mainly used if want to
> + * enable wake IRQ after running ->runtime_suspend() which depends on
> + * WAKE_IRQ_DEDICATED_REVERSE.
> + *
> + * Should be only called from rpm_suspend() path.
> + */
> +void dev_pm_enable_wake_irq_complete(struct device *dev)
> +{
> + struct wake_irq *wirq = dev->power.wakeirq;
> +
> + if (!wirq || !(wirq->status & WAKE_IRQ_DEDICATED_MASK))
> + return;
> +
> + if (wirq->status & WAKE_IRQ_DEDICATED_MANAGED &&
> + wirq->status & WAKE_IRQ_DEDICATED_REVERSE)
> + enable_irq(wirq->irq);
> +}
> +
> /**
> * dev_pm_arm_wake_irq - Arm device wake-up
> * @wirq: Device wake-up interrupt
> diff --git a/include/linux/pm_wakeirq.h b/include/linux/pm_wakeirq.h
> index cd5b62db9084..e63a63aa47a3 100644
> --- a/include/linux/pm_wakeirq.h
> +++ b/include/linux/pm_wakeirq.h
> @@ -17,8 +17,8 @@
> #ifdef CONFIG_PM
>
> extern int dev_pm_set_wake_irq(struct device *dev, int irq);
> -extern int dev_pm_set_dedicated_wake_irq(struct device *dev,
> - int irq);
> +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 void dev_pm_enable_wake_irq(struct device *dev);
> extern void dev_pm_disable_wake_irq(struct device *dev);
> @@ -35,6 +35,11 @@ static inline int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
> return 0;
> }
>
> +static inline int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
> +{
> + return 0;
> +}
> +
> static inline void dev_pm_clear_wake_irq(struct device *dev)
> {
> }
> --
> 2.18.0
>
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