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[USB device enumeration] - My USB audio device can't be enumermated successfully when to connect to PC directly. But it could be enumerated successfully connect to PC via a USB 3.0 hub RRS feed

  • Question

  • Hi All,

    #My question: My USB audio device can't be enumermated successfully when to connect to PC(Windows) directly. But it could be enumerated successfully connect to PC via a USB 3.0 hub

    #Details:

    I made the USB audio device by an Rockchip RK3128 dev-board. In the board, I built my audio device with USB gadget via OTG.

    When I connected the the device to PC, Windows 7, directly, it failed to enumerated. Checking the log on USB device side, RESET operations failed with many times try.

    When I connected the device to USB 3.0 hub and connected the hub to PC, everything is OK.

    What did hub do for the USB enumeration? What clue of the problem with my device?

    Thanks a lot in advance.

    Many Thanks,

    Tim Jiang

    Thursday, October 15, 2015 1:58 AM

Answers

  • Apparently, the hub is more forgiving than the host port, when it comes to devices that are violating the USB specification. Look here for instructions on how to use the message analyzer to watch the USB bus operation. 

     -Brian


    Azius Developer Training www.azius.com Windows device driver, internals, security, & forensics training and consulting. Blog at www.azius.com/blog

    Thursday, October 15, 2015 2:19 AM
    Moderator

All replies

  • Apparently, the hub is more forgiving than the host port, when it comes to devices that are violating the USB specification. Look here for instructions on how to use the message analyzer to watch the USB bus operation. 

     -Brian


    Azius Developer Training www.azius.com Windows device driver, internals, security, & forensics training and consulting. Blog at www.azius.com/blog

    Thursday, October 15, 2015 2:19 AM
    Moderator
  • Hi Brian, 

    Thank you for your information.

    I found my msitakes.  

    I set the PHY to HS but set controller to FS in USB device side. This mismatch could be fixed by hub but not by PC.

    Could somebody show me more information about it? Thanks.

    Another issue now: The audio device could be enumerated on Ubuntu 14.04 PC but still failed to be enumerated on Windows 7 PC. 

    On Windows 7 PC, "SET POWER"(captutred by USB Trace) was addressed at the end of enumeration.

    Many Thanks,

    Tim Jiang

    Thursday, October 15, 2015 2:50 AM
  • Please create a new question thread; we like to keep the threads focused on a single topic

     -Brian


    Azius Developer Training www.azius.com Windows device driver, internals, security, & forensics training and consulting. Blog at www.azius.com/blog

    Thursday, October 15, 2015 8:03 PM
    Moderator