Re: [PATCH 6/9] PM: Add a switch for disabling/enabling asynchronous suspend/resume

Pavel Machek
2009-09-10T10:26:50Z

> From: Rafael J. Wysocki <rjw@sisk.pl>
>
> Add sysfs attribute kernel/power/pm_async allowing the user space to
> disable and enable async suspend/resume of devices.

for bisect reasons, should this go before 5?

>
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
> drivers/base/power/main.c | 13 +++++++------
> drivers/base/power/power.h | 6 +++---
> kernel/power/main.c | 31 ++++++++++++++++++++++++++++++-
> 3 files changed, 40 insertions(+), 10 deletions(-)
>
> Index: linux-2.6/kernel/power/main.c
> ===================================================================
> --- linux-2.6.orig/kernel/power/main.c
> +++ linux-2.6/kernel/power/main.c
> @@ -44,6 +44,32 @@ int pm_notifier_call_chain(unsigned long
> == NOTIFY_BAD) ? -EINVAL : 0;
> }
>
> +/* If set, devices may be suspended and resumed asynchronously. */
> +int pm_async_enabled = 1;
> +
> +static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "%d\n", pm_async_enabled);
> +}
> +
> +static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
> + const char *buf, size_t n)
> +{
> + unsigned long val;
> +
> + if (strict_strtoul(buf, 10, &val))
> + return -EINVAL;
> +
> + if (val > 1)
> + return -EINVAL;
> +
> + pm_async_enabled = val;
> + return n;
> +}
> +
> +power_attr(pm_async);
> +
> #ifdef CONFIG_PM_DEBUG
> int pm_test_level = TEST_NONE;
>
> @@ -208,9 +234,12 @@ static struct attribute * g[] = {
> #ifdef CONFIG_PM_TRACE
> &pm_trace_attr.attr,
> #endif
> -#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
> +#ifdef CONFIG_PM_SLEEP
> + &pm_async_attr.attr,
> +#ifdef CONFIG_PM_DEBUG
> &pm_test_attr.attr,
> #endif
> +#endif
> NULL,
> };
>
> Index: linux-2.6/drivers/base/power/main.c
> ===================================================================
> --- linux-2.6.orig/drivers/base/power/main.c
> +++ linux-2.6/drivers/base/power/main.c
> @@ -235,7 +235,7 @@ static int device_pm_wait_fn(struct devi
> */
> static void device_pm_wait_for_masters(struct device *slave)
> {
> - if (!pm_trace_enabled)
> + if (pm_async_enabled && !pm_trace_enabled)
> device_for_each_master(slave, slave, device_pm_wait_fn);
> }
>
> @@ -245,7 +245,8 @@ static void device_pm_wait_for_masters(s
> */
> static void device_pm_wait_for_slaves(struct device *master)
> {
> - device_for_each_slave(master, master, device_pm_wait_fn);
> + if (pm_async_enabled)
> + device_for_each_slave(master, master, device_pm_wait_fn);
> }
>
> /**
> @@ -560,7 +561,7 @@ static int device_resume_noirq(struct de
> if (pm_op_started(dev))
> return 0;
>
> - if (dev->power.async_suspend && !pm_trace_enabled) {
> + if (pm_async_enabled && !pm_trace_enabled && dev->power.async_suspend) {
> async_schedule(async_resume_noirq, dev);
> return 0;
> }
> @@ -719,7 +720,7 @@ static int device_resume(struct device *
> if (pm_op_started(dev))
> return 0;
>
> - if (dev->power.async_suspend && !pm_trace_enabled) {
> + if (pm_async_enabled && !pm_trace_enabled && dev->power.async_suspend) {
> get_device(dev);
> async_schedule(async_resume, dev);
> return 0;
> @@ -965,7 +966,7 @@ static int device_suspend_noirq(struct d
> if (pm_op_started(dev))
> return 0;
>
> - if (dev->power.async_suspend) {
> + if (pm_async_enabled && dev->power.async_suspend) {
> async_schedule(async_suspend_noirq, dev);
> return 0;
> }
> @@ -1139,7 +1140,7 @@ static int device_suspend(struct device
> if (pm_op_started(dev))
> return 0;
>
> - if (dev->power.async_suspend) {
> + if (pm_async_enabled && dev->power.async_suspend) {
> get_device(dev);
> async_schedule(async_suspend, dev);
> return 0;
> Index: linux-2.6/drivers/base/power/power.h
> ===================================================================
> --- linux-2.6.orig/drivers/base/power/power.h
> +++ linux-2.6/drivers/base/power/power.h
> @@ -16,10 +16,10 @@ static inline void pm_runtime_remove(str
>
> #ifdef CONFIG_PM_SLEEP
>
> -/*
> - * main.c
> - */
> +/* kernel/power/main.c */
> +extern int pm_async_enabled;
>
> +/* drivers/base/power/main.c */
> extern struct list_head dpm_list; /* The active device list */
>
> static inline struct device *to_device(struct list_head *entry)

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