On Sat, Mar 19, 2011 at 12:27:45PM -0400, Alan Stern wrote: > The exact requirement, as stated in the USB 3.0 specification, is this: > > The device descriptor of a SuperSpeed capable device has > a version number of 3.0 (0300H). > > It seems pretty clear that the bcdUSB value doesn't depend on the > device's current speed; it depends only on whether the device is > capable of running at SuperSpeed. But these gadgets won't work at USB 3.0 speeds when plugged into a USB 3.0 host, correct? Why change that now, instead of later when the devices actually do support SuperSpeed? I don't know if it even makes sense for all these gadgets to be SuperSpeed devices later. USB 3.0 is still fairly new, and the USB device class specifications haven't been updated for that yet. For example, how is a USB 3.0 webcam supposed to work, now that there are additional isochronous transfer opportunities per frame (over USB 2.0 isoc devices). We don't know yet. There are some devices that I doubt will ever be marketable as USB 3.0 devices. A USB 3.0 to serial adapter? A USB 3.0 mouse? (Maybe for the power savings, but I doubt any company will want the added expense for the USB 3.0 PHY.) So why change the bcdUSB value prematurely for all gadget drivers? Why not add support to the gadget interface and then see which gadget drivers really need USB 3.0 support? Sarah Sharp -- 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
