Ihor Dutchak

Looks like this is your problem: ```c opts[0] = backOpt; ``` Should be: ```c opts[1] = backOpt; ```

OK, I've checked the code and confirm - there is a bug for this scenario: We try to set the UsbDK option [here](https://github.com/libusb/libusb/blob/de38189e8014fa393f4d8c1d9d3fdf5e2a95899d/libusb/core.c#L2499), and it fails [here](https://github.com/libusb/libusb/blob/de38189e8014fa393f4d8c1d9d3fdf5e2a95899d/libusb/os/windows_common.c#L615), since UsbDK [initialisation](https://github.com/libusb/libusb/blob/de38189e8014fa393f4d8c1d9d3fdf5e2a95899d/libusb/os/windows_common.c#L536)...

> I hope there is a quicker fix for this Some quick (and a bit dirty) fix for this particualar one (not tested): ```diff diff --git a/libusb/core.c b/libusb/core.c index 676c397e..06c59b57...

@SuibianP would you be able to check if #707 brings any improvement for your case?

Add a comment explaining that it has to stay in that order an why

Should we document [here](https://github.com/libusb/libusb/blob/e793d4658b2361b7eecf5a336046c1ced2df9b71/libusb/sync.c#L82) that the value supposed to be a combination of bitfields of `enum libusb_request_type`?

Maybe need to do #39 first, so CMake package is as much alike to autotools one as possible.

I don't see anythiong obvious in the Wireshark capture or the [write.log](https://github.com/user-attachments/files/17170597/write.log) file. What I do see, is that the `hid_write` function performs w/o hang, and exits normally/successfully. Also, `hid_write`...

Hm, maybe you *have to* read the date after you request it by `hid_write`? You will not be able to do it with hidapitester. You would need to write a...

> Is it safe to assume the issue lies within the kernel hid module? That is the assumption I'd made. > I was looking into recompiling the latest of usbhid...