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Assertion: *** DPC watchdog timeout RRS feed

  • Question

  • Hi All,

    Im writing a WiFi driver for windows 7 OS, and facing few hangups during a data transfer test.To resolve these issues, I have configured windbg on remote host via UART interface.

    While testing, frequently observed the following issue, and unable to make progress, any idea on how to overcome/bypass the following issue.

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    Assertion: *** DPC watchdog timeout
        This is NOT a break in update time
        This is most likely a BUG in an ISR
        Perform a stack trace to find the culprit
        The period will be doubled on continuation
        Use gh to continue!!


    Srinivas Reddy. CH

    Friday, April 15, 2016 4:42 AM

Answers

  • You are running for too long a time at DISPATCH_LEVEL or greater.  Take a look at your ISR and DPC routines, plus any place you hold a spin lock, one of these place you are attempting to do a lot of work while at higher IRQL.  You need to split that work into pieces, or move the work to a routine that can handle it a lower IRQL.


    Don Burn Windows Driver Consulting Website: http://www.windrvr.com

    • Marked as answer by Brian Catlin Saturday, April 16, 2016 11:36 PM
    Friday, April 15, 2016 11:48 AM

All replies

  • You are running for too long a time at DISPATCH_LEVEL or greater.  Take a look at your ISR and DPC routines, plus any place you hold a spin lock, one of these place you are attempting to do a lot of work while at higher IRQL.  You need to split that work into pieces, or move the work to a routine that can handle it a lower IRQL.


    Don Burn Windows Driver Consulting Website: http://www.windrvr.com

    • Marked as answer by Brian Catlin Saturday, April 16, 2016 11:36 PM
    Friday, April 15, 2016 11:48 AM
  • Hi Don,

    Thanks for the information.

    Is there any way to disable the DPC wathdog


    Srinivas Reddy. CH

    Tuesday, April 19, 2016 5:10 AM
  • No there is no way to disable it.  If you could disable it you would just be messing up all the other drivers in the system, which expect a certain response time. 

    You need to analyze what you are doing in your driver that takes so long, and move the work to a worker thread or in some other way break up the effort.


    Don Burn Windows Driver Consulting Website: http://www.windrvr.com

    Tuesday, April 19, 2016 10:39 AM
  • Is there any way to disable the DPC wathdog

    As the message in debugger says:  to continue debugging, you can type "gh" (go with exception handled), and the timeout will be doubled.

    - pa

    Tuesday, April 19, 2016 1:03 PM