On Fri, Aug 16, 2013 at 10:42:10AM -0400, Alan Stern wrote: > Okay, let's see if I understand your problem. You've got a driver that ... > Is that it? Yes, I think that's it. > The difficulty with the first proposal is that subsystems aren't > designed to allow that sort of thing. They expect to be able to > communicate with the devices they manage, during enumeration and > probing at least. The difficulty with the second proposal is that it > requires duplicating the power-on code. > My feeling is that the second answer involves less work and less > complexity than the first. Both proposals require additional > "run-once" code (to do the partial instantiations or the initial > power-ons), but the first proposal also requires the subsystem's > detection and enumeration routines to be adjusted so that they can work > even when the device is incommunicado. Right, but like I say I'm not sure that the modifications required are substantially different to those for handling a device powering up and down on the bus or those for getting platform data to a device when it does enumerate. I'd also not be so sure about the run once code, that is only the case for devices that can't completely idle themselves at runtime. > (The second proposal also has the advantage that the power-on code may > be shared between the driver and the subsystem.) Can you explain in more detail please, I don't follow?
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