libusb usb_interrupt_read hangs under FreeBSD

[M. Warner Losh]

In message: <a276da400707071725x2b2b8ab3ife6c5459d06042bd at mail.gmail.com>
            "Xiaofan Chen" <xiaofanc at gmail.com> writes:
: On 7/5/07, Hans Petter Selasky <hselasky at c2i.net> wrote:
: > > > > The chip does not handle a clear-stall request on the control pipe to
: > > > > clear-stall on the interrupt pipe. The result is that the interrupt
: > > > > pipe stops, or at least all buffers are cleared.
: > > > >
: 
: The following is part of the usb firmware from Micrcohip.

I never learned the details, but a client of mine was able to get
fixes from Microchip for their product.  The exact problem was that
endpoint stall clearing didn't work for these devices and it was a
firmware bug.

Warner