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Kinetis K20 and WINUSB on windows 10

Question asked by Ryan Lush on Jun 18, 2018

I have a K20 based WINUSB device that fails to start automatically in Windows 10. When I plug it in it shows up in device manager under Universal Serial Bus Devices with the proper name and a question mark. When I look at the enumeration process in the USB Beagle debugger I can see that it failed. On the 3rd call to get device descriptor by the host, the device responds with an empty data packet and Windows gives up.

Whats strange is if I right click the device in device manager and select uninstall the device starts. It goes through a different enumeration process by making some control transfers rather than request the MS extended compatibility ID OS feature descriptor but it works.

If I unplug the device and plug it back in we are back to the question mark. With or without the question mark the device is using winusb.sys as the driver.

Any ideas as to what I might be doing wrong? This is only a problem on Windows 10 and only with a very small percentage of our devices.

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