Subject: Re: PNP power management API for drivers
To: Jared D.McNeill <>
From: Matt Thomas <>
List: tech-kern
Date: 10/16/2007 13:20:16
On Oct 16, 2007, at 11:03 AM, Jared D. McNeill wrote:

> On Tue, 16 Oct 2007, Jason Thorpe wrote:
>> On Oct 5, 2007, at 6:56 PM, Matt Thomas wrote:
>>> void pnp_domain_join(device_t domain, device_t self)
>> Is it really appropriate to represent the power domain as a  
>> device_t?  I'm beginning to thing that representing all of these  
>> control structures as devices is wrong-headed.
> Maybe I'm missing the point, but what exactly does a power domain  
> provide? The purpose of PNP power management is that device class  
> policies will handle device power automatically.. ie MI audio  
> automatically powers on/off the host audio controller and codecs on  
> an as-needed basis.

this chip has N unrelated devices in a single power domain.  powering  
down the
domain saves more power than individually powering all the devices in  
that domain.