I am running into trouble calling libusb_open in C++ on Linux (running on Raspberry Pi but virtualized to x86 using Exagear).
I can find a device using libusb_get_device_list but it appears translating a device to a device handler using libusb_open is causing problems, even though it returns a 0 (success), however no further commands work. It is giving me the error:
libusb: error [op_open] getcap failed (22)
UPDATE
A little bit of digging has revealed that the following command is producing the error (within libusb):
r = ioctl(hpriv->fd, IOCTL_USBFS_GET_CAPABILITIES, &hpriv->caps);
where IOCTL_USBFS_GET_CAPABILITIES is _IOR('U', 26, __u32). Digging has revealed that error 22 from ioctl is an invalid argument. I'm still trying to unpick this, but any help here is greatly appreciated.