Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8)

[Bryan Huntsman]

> > 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/