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[05/14] PM / doc: update device documentation for devices in IRQ safe PM domains

Message ID 1466624209-27432-6-git-send-email-lina.iyer@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Lina Iyer June 22, 2016, 7:36 p.m. UTC
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(-)

Comments

Kevin Hilman July 25, 2016, 10:50 p.m. UTC | #1
Lina Iyer <lina.iyer@linaro.org> writes:

> 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

minor nit: By "devices" here, I think you mean the runtime PM callbacks for
devices?  If so, it should be explicit, otherwise it's not clear what it
means for devices to operate in process context.

Kevin
Lina Iyer July 25, 2016, 11:21 p.m. UTC | #2
On Mon, Jul 25 2016 at 16:50 -0600, Kevin Hilman wrote:
>Lina Iyer <lina.iyer@linaro.org> writes:
>
>> 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
>
>minor nit: By "devices" here, I think you mean the runtime PM callbacks for
>devices?  If so, it should be explicit, otherwise it's not clear what it
>means for devices to operate in process context.
>
You are right. Its runtime PM that is of interest here.

Thanks,
Lina
diff mbox

Patch

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,