From owner-freebsd-usb@FreeBSD.ORG  Mon Jun 27 19:55:50 2011
Return-Path: <owner-freebsd-usb@FreeBSD.ORG>
Delivered-To: freebsd-usb@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 5993D1065672
	for <freebsd-usb@freebsd.org>; Mon, 27 Jun 2011 19:55:50 +0000 (UTC)
	(envelope-from hselasky@c2i.net)
Received: from swip.net (mailfe04.c2i.net [212.247.154.98])
	by mx1.freebsd.org (Postfix) with ESMTP id D75258FC1C
	for <freebsd-usb@freebsd.org>; Mon, 27 Jun 2011 19:55:49 +0000 (UTC)
X-Cloudmark-Score: 0.000000 []
X-Cloudmark-Analysis: v=1.1 cv=D/a7r8P9hO61Jx2CeejZiK+y1MY0zppvClPbOUfMbas=
	c=1 sm=1 a=SvYTsOw2Z4kA:10 a=WQU8e4WWZSUA:10 a=8nJEP1OIZ-IA:10
	a=CL8lFSKtTFcA:10 a=i9M/sDlu2rpZ9XS819oYzg==:17
	a=4P-ue2ylVXJI09EBBWEA:9 a=wPNLvfGTeEIA:10
	a=i9M/sDlu2rpZ9XS819oYzg==:117
Received: from [188.126.198.129] (account mc467741@c2i.net HELO
	laptop002.hselasky.homeunix.org)
	by mailfe04.swip.net (CommuniGate Pro SMTP 5.2.19)
	with ESMTPA id 145127337; Mon, 27 Jun 2011 21:55:47 +0200
From: Hans Petter Selasky <hselasky@c2i.net>
To: Luca Pizzamiglio <l.pizzamiglio@bally-wulff.de>
Date: Mon, 27 Jun 2011 21:54:05 +0200
User-Agent: KMail/1.13.5 (FreeBSD/8.2-STABLE; KDE/4.4.5; amd64; ; )
References: <4E084297.2040200@bally-wulff.de>
	<201106271320.34494.hselasky@c2i.net>
	<4E0894ED.1060109@bally-wulff.de>
In-Reply-To: <4E0894ED.1060109@bally-wulff.de>
X-Face: *nPdTl_}RuAI6^PVpA02T?$%Xa^>@hE0uyUIoiha$pC:9TVgl.Oq, NwSZ4V"|LR.+tj}g5
	%V,x^qOs~mnU3]Gn; cQLv&.N>TrxmSFf+p6(30a/{)KUU!s}w\IhQBj}[g}bj0I3^glmC(
	:AuzV9:.hESm-x4h240C`9=w
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Message-Id: <201106272154.05183.hselasky@c2i.net>
Cc: freebsd-usb@freebsd.org
Subject: Re: Read from bulk end point
X-BeenThere: freebsd-usb@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: FreeBSD support for USB <freebsd-usb.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-usb>
List-Post: <mailto:freebsd-usb@freebsd.org>
List-Help: <mailto:freebsd-usb-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-usb>,
	<mailto:freebsd-usb-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 27 Jun 2011 19:55:50 -0000

On Monday 27 June 2011 16:34:21 Luca Pizzamiglio wrote:
> Hi,
> 
> the buffer size mitigates the pre-fetch, but could not remove it all...
> Setting 1 as buffer size, the pre-fetch is reduces as 3 wMaxPacketSize
> IN transaction on the bus, but could not avoid it.
> 
> There is a way to disable pre-fetch features? Or better, HPS could you
> point me where is implemented? (just to save time studying source code!)
> 
> Is the prefetch also enabled for Interrupt end point? maybe I could have
> push to correctly redesign this USB board...
> 

Hi,

Have a look in sys/dev/usb/usb_generic.c

Also try to watch the traffic using usbdump.

--HPS

> thanks in advance!
> 
> Luca
> 
> On 06/27/11 13:20, Hans Petter Selasky wrote:
> > On Monday 27 June 2011 13:14:55 Luca Pizzamiglio wrote:
> >> It was strange, because for other endpoints I don't see this kind of
> >> behavior.
> > 
> > Hi,
> > 
> > That is perhaps because they send less data than wMaxPacketSize.
> > 
> > --HPS