| Message ID | 1475699519-109623-9-git-send-email-lina.iyer@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 5 October 2016 at 22:31, Lina Iyer <lina.iyer@linaro.org> wrote: > Update documentation to reflect the changes made to support IRQ safe PM > domains. > > Signed-off-by: Lina Iyer <lina.iyer@linaro.org> > --- > Documentation/power/devices.txt | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt > index 8ba6625..a622136 100644 > --- a/Documentation/power/devices.txt > +++ b/Documentation/power/devices.txt > @@ -607,7 +607,17 @@ 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. 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 be true. Power domains by default, This doesn't make much sense. First, I think you should mention that this is about which context the device's corresponding runtime PM callbacks are allowed to execute in. Second, it's not clear *why* you must set the irq_safe boolean inside struct generic_pm_domain to true, for IRQ-safe devices. You probably shouldn't state this at all. Perhaps a better description is to elaborate on the constraints an IRQ-safe device holds. Then one could explain a bit about how IRQ safe (genpd) PM domains can be used for these devices (something like below). > +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, > +IRQ safe PM domains that have IRQ safe devices may be powered off when all > +the devices are in idle. An IRQ safe domain may only be attached as a > +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, > -- > 2.7.4 > Kind regards Uffe
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 8ba6625..a622136 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -607,7 +607,17 @@ 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. 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 be true. Power domains by 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, +IRQ safe PM domains that have IRQ safe devices may be powered off when all +the devices are in idle. An IRQ safe domain may only be attached as a +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,
Update documentation to reflect the changes made to support IRQ safe PM domains. Signed-off-by: Lina Iyer <lina.iyer@linaro.org> --- Documentation/power/devices.txt | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)