On Fri, 11 Mar 2011, Andy Green wrote: > > Like I say, it's not just MAC addresses that can need configuring this > > way - it can be other random "you're wired up this way" type > > information that would normally be figured out from the USB IDs. > > Yes that's exactly why I was thinking it's a class of requirement that > could reasonably be a little API and extending platform_data to it. So > anyone with onboard USB device can take advantage if they need to, > because I guess we see gradually more boards like that. > > The driver knows well all about the actual device, but there is a class > of configuration information that is defined by the physical board > itself - as you say "how it is wired" - and needs to be passed into the > driver to inform it of its "functional configuration". When that > functional configuration information is a feature of the board alone, > actually the board definition file is the right place for it. I don't see the point of doing this for USB devices, or hot-pluggable devices in general. Suppose you bought another USB device that was just like the on-board one, and plugged it into the system. Why should the driver need to treat the on-board device any different from the hot-plugged device? Or to put it another way... With external, hot-plugged USB devices, there is no need to know "how it is wired". The fact that it is on a USB bus is the only information necessary. Why does anyone need to know more than this for on-board USB devices? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
