Messages in this thread | | | Date | Thu, 03 Jun 2010 14:50:39 -0700 | From | Bryan Huntsman <> | Subject | Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) |
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>> Yes, having a QoS parameter per-subsystem (or even per-device) is very >> important for SoCs that have independently controlled powerdomains. >> If all devices/subsystems in a particular powerdomain have QoS >> parameters that permit, the power state of that powerdomain can be >> lowered independently from system-wide power state and power states of >> other power domains. >> > This seems similar to that pm_qos generalization into bus drivers we where > waving our hands at during the collab summit in April? We never did get > into meaningful detail at that time. > > --mgross
I think there is definitely a need for QoS parameters per-device. I've been pondering how to incorporate this concept into runtime_pm. One idea would be to add pm_qos-like callbacks to struct dev_pm_ops, e.g. runtime_pm_qos_add/update/remove_requirement(). Requirements would be passed up the tree to the first parent that cares, usually a bus driver. Is this similar to what you guys were discussing at the collab summit? Thanks.
- Bryan
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