On Wed, Nov 12, 2014 at 1:22 AM, Richard Bryan <rabr...@lucidsci.com> wrote: > I'm frequently running into an "Access Denied (insufficient permissions)" > errors on Windows 7 (with libusb1 backend) during long-running usb sessions > with a device. When this happens, I call reset() and dispose_resources() on > the usb handle and then attempt to reenumerate it using usb.core.find(), but > the Access Denied error keeps occurring until I unplug and replug the > device. Restarting the program alone doesnt fix it.
libusb under Windows do not support libusb_reset() since WinUSB driver does not support reset. BTW, what is the libusb version you are using? You should use the latest libusb-1.0.19 version. > I have a multithreaded program, but interaction with pyusb is only ever done > in the same, single thread. > > Anyone have any ideas what's going on? Or is this something I should ask > the libusb list about? > You can follow Wander's advice to turn on PYUSB_DEBUG=debug for pyusb debug message. If that is not good enough, you can turn on libusb debug by setting env variable LIBUSB_DEBUG=4 for libusb debug messages. And when this happen, you can check if your USB device is still recognized by Windows in Device Manager? If not, then libusb will fail and most likely your device has a HW/FW stability problem. -- Xiaofan ------------------------------------------------------------------------------ Comprehensive Server Monitoring with Site24x7. Monitor 10 servers for $9/Month. Get alerted through email, SMS, voice calls or mobile push notifications. Take corrective actions from your mobile device. http://pubads.g.doubleclick.net/gampad/clk?id=154624111&iu=/4140/ostg.clktrk _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users
