On 02/12, Lina Iyer wrote:
> diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt
> index 8ba6625..c06f0b6 100644
> --- a/Documentation/power/devices.txt
> +++ b/Documentation/power/devices.txt
> @@ -607,7 +607,16 @@ individually. Instead, a set of devices sharing a power resource can be put
> into a low-power state together at the same time by turning off the shared
> power resource. Of course, they also need to be put into the full-power state
> together, by turning the shared power resource on. A set of devices with this
> -property is often referred to as a power domain.
> +property is often referred to as a power domain. A power domain may also be
> +nested inside another power domain.
> +
> +Devices, by default, operate in process context and if a device can operate in
> +IRQ safe context, has to be explicitly set as IRQ safe. Power domains by
Devices, by default, operate in process context. If a device can
operate in IRQ safe context that has to be explicitly indicated
by setting the irq_safe boolean inside struct generic_pm_domain
to true. Power domains typically operate in process context...
> +default, operate in process context but could have devices that are IRQ safe.
> +Such power domains cannot be powered on/off during runtime PM. On the other
> +hand, an IRQ safe PM domains that have IRQ safe devices may be powered off
On the other hand, IRQ safe PM domains that have ..
> +when all the devices are in idle. An IRQ safe domain may only be attached as a
all the devices in the domain?
> +subdomain to another IRQ safe domain.
>
> Support for power domains is provided through the pm_domain field of struct
> device. This field is a pointer to an object of type struct dev_pm_domain,
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 8204615..3c4f675 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -75,11 +75,59 @@ static struct genpd_lock_fns irq_lock = {
> .unlock = genpd_unlock_irq,
> };
>
> +static void genpd_lock_nosleep(struct generic_pm_domain *genpd)
> + __acquires(&genpd->slock)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&genpd->slock, flags);
> + genpd->lock_flags = flags;
> +}
> +
> +static void genpd_lock_nosleep_nested(struct generic_pm_domain *genpd,
> + int depth)
> + __acquires(&genpd->slock)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave_nested(&genpd->slock, flags, depth);
> + genpd->lock_flags = flags;
> +}
> +
> +static int genpd_lock_nosleep_interruptible(struct generic_pm_domain *genpd)
> + __acquires(&genpd->slock)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&genpd->slock, flags);
> + genpd->lock_flags = flags;
> + return 0;
genpd_lock_nosleep(genpd);
return 0;
> +}
> +
> +static void genpd_unlock_nosleep(struct generic_pm_domain *genpd)
> + __releases(&genpd->slock)
> +{
> + spin_unlock_irqrestore(&genpd->slock, genpd->lock_flags);
> +}
> +
> +static struct genpd_lock_fns no_sleep_lock = {
const?
> + .lock = genpd_lock_nosleep,
> + .lock_nested = genpd_lock_nosleep_nested,
> + .lock_interruptible = genpd_lock_nosleep_interruptible,
> + .unlock = genpd_unlock_nosleep,
> +};
> +
> #define genpd_lock(p) p->lock_fns->lock(p)
> #define genpd_lock_nested(p, d) p->lock_fns->lock_nested(p, d)
> #define genpd_lock_interruptible(p) p->lock_fns->lock_interruptible(p)
> #define genpd_unlock(p) p->lock_fns->unlock(p)
>
> +static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev,
> + struct generic_pm_domain *genpd)
> +{
> + return dev->power.irq_safe && !genpd->irq_safe;
> +}
> +
> /*
> * Get the generic PM domain for a particular struct device.
> * This validates the struct device pointer, the PM domain pointer,
> @@ -510,8 +570,11 @@ static int pm_genpd_runtime_resume(struct device *dev)
> if (IS_ERR(genpd))
> return -EINVAL;
>
> - /* If power.irq_safe, the PM domain is never powered off. */
> - if (dev->power.irq_safe) {
> + /*
> + * As we dont power off a non IRQ safe domain, which holds
s/dont/don't/
> + * an IRQ safe device, we dont need to restore power to it.
s/dont/don't/
> + */
> + if (dev->power.irq_safe && !genpd->irq_safe) {
> timed = false;
> goto out;
> }
> @@ -1296,6 +1359,13 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
> if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
> return -EINVAL;
>
> + if (genpd->irq_safe && !dev->power.irq_safe) {
> + dev_err(dev,
> + "PM Domain %s is IRQ safe; device has to IRQ safe.\n",
has to be?
> + genpd->name);
> + return -EINVAL;
> + }
> +
> gpd_data = genpd_alloc_dev_data(dev, genpd, td);
> if (IS_ERR(gpd_data))
> return PTR_ERR(gpd_data);
> @@ -1394,6 +1464,17 @@ int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
> || genpd == subdomain)
> return -EINVAL;
>
> + /*
> + * If the domain can be powered on/off in an IRQ safe
> + * context, ensure that the subdomain can also be
> + * powered on/off in that context.
> + */
> + if (!genpd->irq_safe && subdomain->irq_safe) {
> + WARN("Parent %s of subdomain %s must be IRQ-safe\n",
Nitpick! IRQ-safe or IRQ safe? Use one consistently please.
> + genpd->name, subdomain->name);
> + return -EINVAL;
> + }
> +
> link = kzalloc(sizeof(*link), GFP_KERNEL);
> if (!link)
> return -ENOMEM;
--
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