On Friday, October 21, 2016 03:52:55 PM Lina Iyer wrote: > Update documentation to reflect the changes made to support IRQ safe PM > domains. > > Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx> > Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> > --- > Changes since v3: > - Moved para to the end of the section > - Added clause for all IRQ safe devices in a domain > - Cleanup explanation of nested domains > --- > Documentation/power/devices.txt | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt > index 8ba6625..9218ce6 100644 > --- a/Documentation/power/devices.txt > +++ b/Documentation/power/devices.txt > @@ -607,7 +607,9 @@ 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. The nested domain is referred to as the > +sub-domain of the parent 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, > @@ -629,6 +631,13 @@ support for power domains into subsystem-level callbacks, for example by > modifying the platform bus type. Other platforms need not implement it or take > it into account in any way. > > +Devices and PM domains may be defined as IRQ-safe, if they can be powered > +on/off even when the IRQs are disabled. What IRQ-safe means for devices is that their runtime PM callbacks may be invoked with interrupts disabled on the local CPU. I guess the meaning of IRQ-safe for PM domains is analogous, but the above isn't precise enough to me. > An IRQ-safe device in a domain will > +disallow power management on the domain, unless the domain is also defined as > +IRQ-safe. In other words, a domain containing all IRQ-safe devices must also > +be defined as IRQ-safe. Another restriction this framework imposes on the > +parent domain of an IRQ-safe domain is that the parent domain must also be > +defined as IRQ-safe. What about this: "Devices may be defined as IRQ-safe which indicates to the PM core that their runtime PM callbacks may be invoked with disabled interrupts (see Documentation/power/runtime_pm.txt for more information). If an IRQ-safe device belongs to a PM domain, the runtime PM of the domain will be disallowed, unless the domain itself is defined as IRQ-safe. However, a PM domain can only be defined as IRQ-safe if all of the devices in it are IRQ-safe. Moreover, if an IRQ-safe domain has a parent domain, the runtime PM of the parent is only allowed if the parent itself is IRQ-safe too with the additional restriction that all child domains of an IRQ-safe parent must also be IRQ-safe." Does it actually reflect what the code does? Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
