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Re-enumeration of first usb device when second usb device is connected RRS feed

  • Question

  • Hi,

    i am newbie in windows device drivers development.

    I am debugging a USB driver issue when two devices are connected.

    Below is the scenario:

    1. 1st device is connected and enumerated; here data exchange is happening on this device though a PC application without any problem.

    2. 2st device is connected and enumerated; here data exchange is happening on this device though a PC application without any problem.

    3. now i am resetting the second device for every 1 min by some script.When 2nd device is reset, we see 1st device getting re-enumerated, which is resulting in discontinuation of the data exchange.

    This behavior was rarely seen when we connect this setup to the external hub.

    Both the devices are using the same custom USB driver and both device are same type.(connecting multiple same devices)

    Appreciate if someone assist in finding the cause for this.


    Wednesday, April 20, 2016 5:10 AM

All replies

  • are you seeing this behavior when the devices share the same parent hub?

    d -- This posting is provided "AS IS" with no warranties, and confers no rights.

    Wednesday, April 20, 2016 6:45 AM
  • thank you for reply.

    No.when ever we connect the devices directly to the PC ports without external hub this behavior in not seen.only when we connected an external hub and devices to that hub.

    Latest observation:when we connect three devices to external hub and resetting the second device(port2), then only the devices which are connected to lower ports(port1) of the hub getting effected but no effect on device which is connected to upper ports(port3).

    if we connected the four device also same behavior observed. only lower port devices getting effected even if we reset third device(port3) then port1 and port2 device getting reenumerated but no effect on port4 device.

    Note:this test running for 2 days but this behavior observed every few hours once.  

    Wednesday, April 20, 2016 7:30 AM
  • What if you connect these devices to TWO different hubs (and the hubs have external power)?

    --pa

    Wednesday, April 20, 2016 4:18 PM
  • This looks like a hub hardware issue. Does the issue repro with a different external hub? 

    One way to debug this would be to use the following tool: https://msdn.microsoft.com/en-us/library/windows/hardware/jj672840%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396 . When you initiate reset on the first device, see if the tool dumps any event about the other port.

    Wednesday, April 20, 2016 5:52 PM
  • No this devices are connected to the same external hub and external hub has external power supply also. 
    Thursday, April 21, 2016 3:38 AM
  • We didn't tried with different external hubs.devices are sharing the same usb hub.

    are you asking the same test with different hubs(manufactures) or the device are sharing the two different hubs.

    we will make use of the this tool for debugging the issue and will let you know result.

    @vivek: this tool is not working in windows 7 operating system.can please give me the link for this tool for indows 7.
    Thursday, April 21, 2016 4:02 AM
  • Unfortunately, this tool will not work on Windows 7. This tool will work only on Windows 8 or higher on a system that has USB 3.0/XHCI controller.
    Friday, April 22, 2016 8:15 PM
  • @Vivek: Thank u. i tried by installing in windows 8.1 also buts its not worked therer also. my pc is not have any usb 3.0 ports. i think so probably it might not have the USB 3.0/XHCI Controller. but in device manger it is showing USB XHCI host controller.

    Monday, April 25, 2016 11:59 AM
  • @Vivek: Thank u. i tried by installing in windows 8.1 also buts its not worked therer also. my pc is not have any usb 3.0 ports. i think so probably it might not have the USB 3.0/XHCI Controller. but in device manger it is showing USB XHCI host controller.

    Hi guys.....

    Any updates regarding this problem. i am unable proced further.

    Tuesday, May 3, 2016 12:20 PM
  • Had you had a chance to test with two hubs or different hub model? Otherwise it looks like your hub is the culprit.

    -- pa

    Tuesday, May 3, 2016 2:31 PM
  • hi pavel

    i am in that process only. trying to check the same thing.let u know the thing after i have done.

    Meanwhile if u guys have any solutions please share with me.

    thank you.

    Wednesday, May 4, 2016 10:53 AM
  • Hi Guys....

    i am back with the same problem.

    i tried the same setup with different external hubs(different vendors). but observed the same issue in all three hubs.

    here our usb device is 1.1 (full speed ) and i am using the usb 3.0 hubs as external hub, is it there any problem with this setup,can we use like this ?.

    where as no issues found while connected to the PC's internal hub directly (no external hub).

    this is blocking me to proceed further. any solutions, any root causes and any other testing way to test this would be more and more helpful for me.

    it would be more appreciations if any thing is provided.

    thank you very in advance. 

    Friday, May 6, 2016 5:33 AM