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

[Sumant O. <soe...@xs...>]

Thanks, it seems that indeed not explicitly calling the set altinterface, works.

Kind regards,
Sumant Oemrawsingh

> Op 15-02-2021 02:10 schreef Xiaofan Chen <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