From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752126AbcKYDtn (ORCPT ); Thu, 24 Nov 2016 22:49:43 -0500 Received: from pb-sasl1.pobox.com ([64.147.108.66]:55728 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750991AbcKYDtm (ORCPT ); Thu, 24 Nov 2016 22:49:42 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=subject:to :references:cc:from:message-id:date:mime-version:in-reply-to :content-type:content-transfer-encoding; q=dns; s=sasl; b=gKHZJ6 CJNU4JkMPCR8Yc2urS1/UbnSFAzUJ6odGmODWwDPGx2f6oSvnNHmVdLSbK7/I6sO PAS4U7ZhIHqbME3DfSORECts7a7ZR9BJ8WD2T1avUfXvn85rrgVmYWzDArAar5V/ x9PRQj+HLmz9S10fyeX39j3rQLf3AMuSbgkYk= Subject: Re: [PATCH net 1/2] r8152: fix the sw rx checksum is unavailable To: Francois Romieu References: <0835B3720019904CB8F7AA43166CEEB201055ED8@RTITMBSV03.realtek.com.tw> <20161124.112152.692025478489876693.davem@davemloft.net> <23e0c132-8844-0a34-3e0b-e412f76493ba@pobox.com> <20161124.121140.2054576632424977475.davem@davemloft.net> <20161125002702.GA14085@electric-eye.fr.zoreil.com> Cc: David Miller , hayeswang@realtek.com, netdev@vger.kernel.org, nic_swsd@realtek.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org From: Mark Lord Message-ID: Date: Thu, 24 Nov 2016 22:49:33 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20161125002702.GA14085@electric-eye.fr.zoreil.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Pobox-Relay-ID: 2E4047EC-B2C2-11E6-93BE-B2316462E9F6-82205200!pb-sasl1.pobox.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16-11-24 07:27 PM, Francois Romieu wrote: > > Through aliasing the URB was given a page that contains said (previously) > received file. The ethernet chip/usb host does not write anything in it. I don't see how that could be possible. Please elaborate. The URB buffers are statically allocated by the driver at probe time, ten of them in all, allocated with usb_alloc_coherent() in the copy of the driver I am testing with. There is no possibility for them to be used for anything other than USB receive buffers, for this driver only. Nothing in the driver or kernel ever writes to those buffers after initial allocation, and only the driver and USB host controller ever have pointers to the buffers. -- Mark Lord