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Date:      Tue, 25 Nov 2008 15:49:05 -0800
From:      Alfred Perlstein <alfred@freebsd.org>
To:        Thierry Herbelot <thierry.herbelot@free.fr>
Cc:        usb@freebsd.org
Subject:   Re: concurrent access to multiple endpoints of a USB device ?
Message-ID:  <20081125234904.GP28578@elvis.mu.org>
In-Reply-To: <200811252228.09926.thierry.herbelot@free.fr>
References:  <200811252228.09926.thierry.herbelot@free.fr>

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* Thierry Herbelot <thierry.herbelot@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.

-- 
- Alfred Perlstein



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