Re: [libusb] Read timeout after first write/read

[Xiaofan C. <xia...@gm...>]

If the configuration setting is not the problem, try to skip the
altinterface setting which is not
necessary and may cause the device to misbehave. Basically based on
your description,
PICKit 3 FW has a problem in dealing with the USB requests. This is
not a libusb problem
but rather device problem.

HIDAPI has two backends under Linux, libusb and hidraw. You can try
hidraw (do not
detach the kernel hid driver) to see if that works or not.

Best regards,
Xiaofan

On Mon, Feb 15, 2021 at 5:54 AM Sumant Oemrawsingh <soe...@xs...> wrote:
>
> Hi Xiaofan,
>
> Thanks for the tips. As written I'm already checking the current config and
> only setting it if needed. As stated, this does not change the described behavior.
>
> The behavior only seems to be correct if I don't claim the interface and don't
> set the altinterface, but that hardly seems a sustainable way to go.
>
> Am I understanding that you are saying that libusb itself cannot handle the
> HID device correctly, and I should use the other library? As I understand HIDAPI
> uses libusb as a backend, so the problem would still persist, I guess. I will try it,
> but I'd prefer getting it working directly with libusb.
>
> Thanks,
> Sumant Oemrawsingh