From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752890Ab1HIJXS (ORCPT <rfc822;w@1wt.eu>);
	Tue, 9 Aug 2011 05:23:18 -0400
Received: from mail-vx0-f174.google.com ([209.85.220.174]:43587 "EHLO
	mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752523Ab1HIJXP convert rfc822-to-8bit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 9 Aug 2011 05:23:15 -0400
MIME-Version: 1.0
In-Reply-To: <4E097A32.1000504@freemail.hu>
References: <4DDBF8BD.3000603@freemail.hu>
	<20110524183448.GA18511@kroah.com>
	<4DDC142E.6070003@freemail.hu>
	<20110525031222.GB14290@haskell.muteddisk.com>
	<4DDC93D5.9070607@freemail.hu>
	<4DDDFDA7.6030900@freemail.hu>
	<4E097A32.1000504@freemail.hu>
Date: Tue, 9 Aug 2011 17:23:14 +0800
X-Google-Sender-Auth: Fsm5vkyqv40S-v_oYLsNuQWeKXA
Message-ID: <CAL-cBk1Kzr1Gn3YCHDpudkVSmdSWOcCo7_rpLddCUQ_3ZjP+kQ@mail.gmail.com>
Subject: Re: [PATCH, RFC] USBIP protocol documentation
From: David Chang <dchang@suse.com>
To: Greg KH <greg@kroah.com>
Cc: =?ISO-8859-1?Q?N=E9meth_M=E1rton?= <nm127@freemail.hu>,
        Matthew Wilcox <matthew@wil.cx>, Max Vozeler <max@vozeler.com>,
        Matt Mooney <mfm@muteddisk.com>, Joe Perches <joe@perches.com>,
        linux-usb@vger.kernel.org, usbip-devel@lists.sourceforge.net,
        devel@driverdev.osuosl.org, LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Greg,

2011/6/28 Németh Márton <nm127@freemail.hu>:
> From: Márton Németh <nm127@freemail.hu>
>
> USBIP v1.0.0 protocol documentation.
>
> Signed-off-by: Márton Németh <nm127@freemail.hu>
> ---
>
> Hi,
>
> I tried to document the USBIP protocol as implemented in the Linux kernel 3.0-rc2.
>
> The description is a preliminary draft only, it may contain mistakes. I tried
> to document what I have understand from the source code and from the actual
> captured network traffic when the USBIP is in action. Please review it, correct it,
> point out the missing parts.
>
> During I have documented the protocol a question came into my mind: why do we
> have two different type of package when the URB completition handler is called,
> namely USB_RET_SUBMIT and USBIP_RET_UNLINK? As far as I can see this causes race
> condition because for one URB the completition handler is only called once. If
> the one URB is sent in with USB_CMD_SUBMIT and then unlinked with USB_CMD_UNLINK
> the completition handler is called only once. In the protocol, however, we have
> two different type of packets: USB_RET_SUBMIT and USBIP_RET_UNLINK. The status
> field of these messages may contain anything in this case depending on the timing.
>
> Regards,
>
>        Márton Németh

Sorry, just one question about the usbip protocol document.
I would like to know why didn't you apply this patch.
Thanks in advance!

Best Regards,
David


>
> _______________________________________________
> devel mailing list
> devel@linuxdriverproject.org
> http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
>