On Wed, Apr 28, 2021 at 01:49:30AM +0000, CM-Wu Ben - 吳文鐘 wrote: > 寄件者: Jonas Malaco via pyusb-users <pyusb-users@lists.sourceforge.net> > 寄件日期: 2021年4月27日 下午 05:16 > 收件者: pyusb-users@lists.sourceforge.net <pyusb-users@lists.sourceforge.net> > 副本: Jonas Malaco <jo...@protocubo.io> > 主旨: Re: [pyusb-users] help on win7: Entity not found > > On Tue, Apr 27, 2021 at 08:18:09AM +0000, CM-Wu Ben - 吳文鐘 wrote: > > Hi, > > I got a problem when dealing with control transfer on win7. > > > > After set backend(libusb1), find usb device, I can send standard/class USB > > request via dev.ctrl_transfer() successfully, but failed when sending > > vendor request. > > > > the reason is 'Entity not found' > > Is there any restrictions when sending vendor request? > > Not generally, no. > > But the OS driver may not support it (e.g. Windows Generic HID). > > Try running with LIBUSB_DEBUG=4, that may give you some useful > information. > ------------------ > > Thanks for your information. > I tried to run with LIBUSB_DEBUG=4, and found that it is windows HID driver > that handle the request, which does not support it. > > The device I'm testing is a composite device, which has audio interface > within it. > Do windows audio driver support the handling of control transfer ?
I don't know. And even if it does, it and/or the device may only accept control transfers through it that are related to that particular interface. My suggestion is for you to install WinUSB with Zadig. See: https://github.com/libusb/libusb/wiki/FAQ#How_to_use_libusb_under_Windows > If yes, is it possible to send control transfer via audio driver? how to do > it using libusb backend? Try to ask in the libusb mailling list. Thanks, Jonas > Thanks > > > > 『The information contained in this email and attachment is confidential and > is for the use of the intended recipient only. Any disclosure, copying or > distribution of this email and attachment without the sender's consent is > strictly prohibited. If you are not the intended recipient, please promptly > notify the sender and delete this email and attachment entirely without > using, retaining, or disclosing any of its contents. The recipient is > responsible for ensuring that this email is virus free and the sender accepts > no liability for any damages caused by virus transmitted by this email.』 > _______________________________________________ > pyusb-users mailing list > pyusb-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/pyusb-users _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users
