On Tue, 12 Apr 2016, John Youn wrote: > > Wait, even SuperSpeed GEN1-only devices *must* set bcdUSB to 0x0310 ? Do > > you have a reference to that ? I find that pretty odd because this means > > that if I take any of my USB3 devices that I already have today, and run > > them against latest USBCV, they'll all fail and that's not very nice. > > Yup, that is exactly what happens. See 9.6.1 in the USB 3.1 > specification. Also the CV tool and compliance test specification from > USB IF say this as well. If you test with any existing SuperSpeed > device it will fail. I have the definite impression that the USB IF is getting more and more careless as it gets older. The first two paragraphs of 9.6.1 are actually contradictory! A device descriptor describes general information about a device. It includes information that applies globally to the device and all of the device’s configurations. A device has only one device descriptor. The device descriptor of an Enhanced SuperSpeed device shall have a version number of 3.1 (0310H). The device descriptor of an Enhanced SuperSpeed device operating in one of the USB 2.0 modes shall have a version number of 2.1 (0210H). If a device has only one device descriptor, how can it have different version numbers at different speeds? Besides, this doesn't say what the version number of a non-Enhanced SuperSpeed device should be. I don't see why the USBCV would conclude that a non-Enhanced device needs to set the version to 0x0310. 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
