concurrent access to multiple endpoints of a USB device ?

[Thierry Herbelot]

Le Wednesday 26 November 2008, Alfred Perlstein a écrit :
> * Thierry Herbelot <thierry.herbelot at free.fr> [081125 13:51] wrote:
> > Hello,
> >
> > (this is with the old USB stack, on a -slow- 7.1 i386 machine)
> >
> > I'm playing with a USB2.0 device which exposes multplie endpoints
> > (control on EP0, then bulk endpoints 1, 2 and 3).
> >
> > When I run a control application doing EP0 requests simultaneously with
> > another process reading off EP2, the reading process only gets errors :
> > "Received -1 vs 65536 bytes requested ep 2 errno=5 (Input/output error)"
> >
> > The control application by itself works correctly.
> >
> > I'm using a simple read system call to read from ugen0.2 :
> > "nb_bytes = read(ep_fd[2], buf, nb);"
> >
> > Is there anything I should do to for example increase the ep2 buffer size
> > ? (maybe I should also try the new USB stabck, for sure)
>
> Give usb2 a shot.  Hans is pretty on top of issues in it.

will do ASAP : thanks for the advice

	TfH