Window XP & 7 USB Reset

[USBVIDPID]

Hi, All.

A USB trace shows USB bus reset while running our application.  We are trying to figure out if the OS is doing this when the device get into an error condition like continuous STALLs or other error condition like no response to  commands or polls.

When will Windows do a bus reset of a device during an application, if ever? 

Thanks.

[Jan Axelson]

Once a device has been enumerated, a port reset is a last-ditch effort to restore communications when something has gone very wrong.

So STALLing an unsupported control request won't trigger a port reset except possibly if the device is STALLING a required request. Several attempts to communicate with no response at all can trigger a port reset. The specifics can vary with the driver.

If you have a trace showing the reset, look at what is happening just before the reset.

Jan