0 Replies Latest reply on Aug 18, 2017 12:47 PM by sstephens_2290246

    Fx3 device descriptor failed on USB bus reset with Windows 10


      I have a problem with the Fx3 SuperSpeed Explorer kit board (also happens on our custom board with the Fx3).  The first time its inserted on the computer, it enumerates fine, but when the machine is rebooted, Windows tells me the device descriptor has a problem.  It only occurs when booted out of the built in ROM and happens on Windows10 and Windows7 with two different computers.  If I use USB boot mode to boot custom firmware, like the streamer example, its fine.  I can make it occur not only on a reboot (without touching the Fx3 board at all or power to it), but if I disable the hub using device manager, then re-enable the hub, it also comes back as code 43 and the same device descriptor failed message.  So I'm guessing its a problem with the firmware in boot ROM not handling a bus reset properly.  But I'm not sure how to fix it because as far as I know, the boot ROM is not updatable.


      When its in code 43 mode, I can't do anything programmatically with it until I manually reset it, so its definitely going to be a problem for our use case.  I have a log from Microsoft's USB 3.0 verifier attached that has some more detail that its failing "Descriptor Validation WarningDescriptorValidationErrorEndpointBlengthTooLarge".


      Any help would be appreciated.