generic power management for USB subsystem similar to PCI one?

Hello,
Currently I am working on removing legacy power management .suspend() and .resume() callbacks from PCI subsystem. The updates aim to give power management control to PCI core and let drivers do the only device-specific jobs without using any PCI helper functions.

I was wondering if similar changes can be applied to the USB subsystem? I explored and found that .suspend() in USB drivers also accept the pm_message_t type argument.
Also, .suspend() and .resume() in usb drivers, accept "struct usb_interface *" type argument which seems similar to PCI legacy drivers accepting "struct pci_dev*" type.

Moreover, "struct usb_device_driver" seems analogous to "struct pci_driver" as it also has .suspend() and .resume() callback. Also, it has a bitfield "generic_subclass:1" which is described as, " @generic_subclass: if set to 1, the generic USB driver's probe, disconnect, resume and suspend functions will be called in addition to the driver's own, so this part of the setup does not need to be replicated. "

So the generic PM, talked about in USB drivers, is similar to PCI one? The non-generic PM in USB is similar to legacy PM in PCI?

A similar update for the USB subsystem is possible?

--Vaibhav Gupta

I don't know what you mean by "the generic PM". IMO, overall USB power management is pretty similar to the arrangement in PCI, although with less legacy stuff remaining.

No, I don't think so, although it's hard to give an exact answer to such an imprecise question. What sort of thing would make USB PM similar to legacy PCI PM?

I think you'll find that the power management in USB drivers already does only device-specific things, with overall control remaining in the USB core.

Maybe if you came up with some more specific examples of what you are thinking of, I could give better answers.

Alan Stern