From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932974AbcKNHYN (ORCPT ); Mon, 14 Nov 2016 02:24:13 -0500 Received: from rtits2.realtek.com ([211.75.126.72]:41642 "EHLO rtits2.realtek.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932109AbcKNHYJ (ORCPT ); Mon, 14 Nov 2016 02:24:09 -0500 Authenticated-By: X-SpamFilter-By: BOX Solutions SpamTrap 5.56 with qID uAE7NpDe030590, This message is accepted by code: ctloc85258 From: Hayes Wang To: Mark Lord , David Miller CC: "netdev@vger.kernel.org" , nic_swsd , "linux-kernel@vger.kernel.org" , "linux-usb@vger.kernel.org" Subject: RE: [PATCH net 2/2] r8152: rx descriptor check Thread-Topic: [PATCH net 2/2] r8152: rx descriptor check Thread-Index: AQHSO+t5Wscn8cAer0W3mKS4Fv3VhKDWq+8AgAAwq4CAATIAMA== Date: Mon, 14 Nov 2016 07:23:51 +0000 Message-ID: <0835B3720019904CB8F7AA43166CEEB20104EBCC@RTITMBSV03.realtek.com.tw> References: <1394712342-15778-226-Taiwan-albertk@realtek.com> <1394712342-15778-228-Taiwan-albertk@realtek.com> <20161113.123954.2134945576362221851.davem@davemloft.net> In-Reply-To: Accept-Language: zh-TW, en-US Content-Language: zh-TW X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [172.21.177.128] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id uAE7OKgK017471 Mark Lord [mailto:mlord@pobox.com] > Sent: Monday, November 14, 2016 4:34 AM [...] > Perhaps the driver > is somehow accessing the buffer space again after doing usb_submit_urb()? > That would certainly produce this kind of behaviour. I don't think so. First, the driver only read the received buffer. That is, the driver would not change (or write) the data. Second, The driver would lose the point address of the received buffer after submitting the urb to the USB host controller, until the transfer is completed by the USB host controller. That is, the driver doesn't how to access the buffer after calling usb_submit_urb(). Best Regards, Hayes