Re: [PATCH v5] Report interrupt(s) that caused system wakeup

From: Rafael J. Wysocki
Date: Fri Aug 07 2015 - 18:10:13 EST


On Thursday, August 06, 2015 08:47:04 PM Alexandra Yates wrote:
> Add a new IRQ flag named IRQD_WAKEUP_TRIGGERED. This flag is set
> when a given IRQ fires after it has been armed for system wakeup.
> The flag is cleared before arming the IRQ for system wakeup
> during the next system suspend. This feature makes possible to
> check which IRQs might have woken the system up from sleep last
> time it was suspended.
>
> Add a new sysfs attribute under /sys/power/ named:pm_last_wakeup_irqs
> when read, will return a list of IRQs with the new flag set. That
> will be useful for system wakeup diagnostics.
>
> Signed-off-by: Alexandra Yates <alexandra.yates@xxxxxxxxxxxxxxx>

Thanks for the patch, but you've forgotten to CC the IRQ subsystem maintainer.

Hi Thomas, can you please have a look at the patch below and tell me if you
have any concerns about it?

Rafael


> ---
> Documentation/ABI/testing/sysfs-power | 11 +++++++++++
> drivers/base/power/wakeup.c | 31 +++++++++++++++++++++++++++++++
> include/linux/irq.h | 7 +++++++
> include/linux/suspend.h | 1 +
> kernel/irq/pm.c | 2 ++
> kernel/power/main.c | 23 +++++++++++++++++++++++
> 6 files changed, 75 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
> index f455181..4f9cc3a 100644
> --- a/Documentation/ABI/testing/sysfs-power
> +++ b/Documentation/ABI/testing/sysfs-power
> @@ -256,3 +256,14 @@ Description:
> Writing a "1" enables this printing while writing a "0"
> disables it. The default value is "0". Reading from this file
> will display the current value.
> +
> +What: /sys/power/pm_last_wakeup_irqs
> +Date: April 2015
> +Contact: Alexandra Yates <alexandra.yates@xxxxxxxxxxxxxxx>
> +Description:
> + The /sys/power/pm_last_wakeup_irqs file allows user space
> + to identify and report the IRQs responsible for waking the
> + system up from sleep. The IRQD_WAKEUP_TRIGGERED flag is set and
> + reported when the given IRQ fires after it has been armed for
> + system wakeup. This output is useful for system wakeup
> + diagnostics.
> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
> index 51f15bc..1a2d13b 100644
> --- a/drivers/base/power/wakeup.c
> +++ b/drivers/base/power/wakeup.c
> @@ -870,6 +870,37 @@ void pm_wakeup_clear(void)
> pm_abort_suspend = false;
> }
>
> +#ifdef CONFIG_PM_SLEEP_DEBUG
> +/*
> + * pm_get_last_wakeup_irqs - Parses interrupts to identify which one
> + * caused the system to wake up from suspend-to-idle.
> + * @buf: keeps track of the irqs that casued the system to wakeup
> + */
> +ssize_t pm_get_last_wakeup_irqs(char *buf, size_t size)
> +{
> + struct irq_desc *desc;
> + int irq;
> + char *str = buf;
> + char *end = buf + size;
> +
> + if (!pm_abort_suspend)
> + return 0;
> +
> + /* If pm_abort_suspend is not set, the previous suspend was aborted
> + * before arming the wakeup IRQs, so avoid printing stale information
> + * in that case.
> + */
> + for_each_irq_desc(irq, desc)
> + if (irqd_triggered_wakeup(&desc->irq_data))
> + str += scnprintf(str, end - str, "%d ", irq);
> +
> + if (str != buf)
> + str--;
> +
> + return (str - buf);
> +}
> +#endif /* CONFIG_PM_SLEEP_DEBUG */
> +
> /**
> * pm_get_wakeup_count - Read the number of registered wakeup events.
> * @count: Address to store the value at.
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index 92188b0..7935e95 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -190,6 +190,7 @@ struct irq_data {
> * IRQD_IRQ_MASKED - Masked state of the interrupt
> * IRQD_IRQ_INPROGRESS - In progress state of the interrupt
> * IRQD_WAKEUP_ARMED - Wakeup mode armed
> + * IRQD_WAKEUP_TRIGGERED - Triggered system wakeup
> */
> enum {
> IRQD_TRIGGER_MASK = 0xf,
> @@ -204,10 +205,16 @@ enum {
> IRQD_IRQ_MASKED = (1 << 17),
> IRQD_IRQ_INPROGRESS = (1 << 18),
> IRQD_WAKEUP_ARMED = (1 << 19),
> + IRQD_WAKEUP_TRIGGERED = (1 << 20),
> };
>
> #define __irqd_to_state(d) ((d)->common->state_use_accessors)
>
> +static inline bool irqd_triggered_wakeup(struct irq_data *d)
> +{
> + return __irqd_to_state(d) & IRQD_WAKEUP_TRIGGERED;
> +}
> +
> static inline bool irqd_is_setaffinity_pending(struct irq_data *d)
> {
> return __irqd_to_state(d) & IRQD_SETAFFINITY_PENDING;
> diff --git a/include/linux/suspend.h b/include/linux/suspend.h
> index 5efe743..7cadded 100644
> --- a/include/linux/suspend.h
> +++ b/include/linux/suspend.h
> @@ -378,6 +378,7 @@ void restore_processor_state(void);
> /* kernel/power/main.c */
> extern int register_pm_notifier(struct notifier_block *nb);
> extern int unregister_pm_notifier(struct notifier_block *nb);
> +extern ssize_t pm_get_last_wakeup_irqs(char *buf, size_t size);
>
> #define pm_notifier(fn, pri) { \
> static struct notifier_block fn##_nb = \
> diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
> index d22786a..1f16aea 100644
> --- a/kernel/irq/pm.c
> +++ b/kernel/irq/pm.c
> @@ -22,6 +22,7 @@ bool irq_pm_check_wakeup(struct irq_desc *desc)
> desc->depth++;
> irq_disable(desc);
> pm_system_wakeup();
> + irqd_set(&desc->irq_data, IRQD_WAKEUP_TRIGGERED);
> return true;
> }
> return false;
> @@ -73,6 +74,7 @@ static bool suspend_device_irq(struct irq_desc *desc, int irq)
> if (!desc->action || desc->no_suspend_depth)
> return false;
>
> + irqd_clear(&desc->irq_data, IRQD_WAKEUP_TRIGGERED);
> if (irqd_is_wakeup_set(&desc->irq_data)) {
> irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED);
> /*
> diff --git a/kernel/power/main.c b/kernel/power/main.c
> index 63d395b..6e550c0 100644
> --- a/kernel/power/main.c
> +++ b/kernel/power/main.c
> @@ -272,6 +272,28 @@ static inline void pm_print_times_init(void)
> {
> pm_print_times_enabled = !!initcall_debug;
> }
> +
> +static ssize_t pm_last_wakeup_irqs_show(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + char *buf)
> +{
> + size_t ret;
> +
> + ret = pm_get_last_wakeup_irqs(buf, PAGE_SIZE);
> + if (ret)
> + buf[ret++] = '\n';
> +
> + return ret;
> +}
> +
> +static ssize_t pm_last_wakeup_irqs_store(struct kobject *kobj,
> + struct kobj_attribute *attr,
> + const char *buf, size_t n)
> +{
> + return -EINVAL;
> +}
> +power_attr(pm_last_wakeup_irqs);
> +
> #else /* !CONFIG_PM_SLEEP_DEBUG */
> static inline void pm_print_times_init(void) {}
> #endif /* CONFIG_PM_SLEEP_DEBUG */
> @@ -604,6 +626,7 @@ static struct attribute * g[] = {
> #endif
> #ifdef CONFIG_PM_SLEEP_DEBUG
> &pm_print_times_attr.attr,
> + &pm_last_wakeup_irqs_attr.attr,
> #endif
> #endif
> #ifdef CONFIG_FREEZER
>

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