Re: Power parents

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Sat, 2004-10-09 at 00:07, Alan Stern wrote:

> My reason for asking is because having special parent pointers like that,
> without corresponding children pointers, makes it impossible to guarantee
> that parents aren't suspended until after their children when doing a
> selective suspend.

Oh, I also remember at one point toying with moving some devices to
different parents based on weird mobo design, but I dropped the idea.

> What sort of special nodes are you thinking of inserting, and how would 
> they affect selective suspend?

Oh, I'm thinking about inserting a "platform" entry between some USB
controllers and the PCI parent. On PowerMac, some of these USB controllers
are power managed via special stuffs in Apple ASICs that aren't directly
related to the PCI bus they sit on. Right now, I have hacks in the USB
HCD drivers themselves for that, but it would be cleaner just to "insert"
an entry in the power tree to do the job.

Ben.