Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756246Ab0BBOgL (ORCPT ); Tue, 2 Feb 2010 09:36:11 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:50136 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753595Ab0BBOgB (ORCPT ); Tue, 2 Feb 2010 09:36:01 -0500 Subject: Re: USB mass storage and ARM cache coherency From: Catalin Marinas To: Ming Lei Cc: Oliver Neukum , Matthew Dharm , Sergei Shtylyov , linux-usb@vger.kernel.org, linux-kernel , Sebastian Siewior , Greg KH In-Reply-To: References: <20100129185434.GH19501@one-eyed-alien.net> <201002021248.10994.oliver@neukum.org> <1265112072.12634.53.camel@pc1117.cambridge.arm.com> <201002021307.56991.oliver@neukum.org> <1265114375.12634.61.camel@pc1117.cambridge.arm.com> Content-Type: text/plain Organization: ARM Ltd Date: Tue, 02 Feb 2010 14:35:48 +0000 Message-Id: <1265121348.12634.76.camel@pc1117.cambridge.arm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 02 Feb 2010 14:35:50.0027 (UTC) FILETIME=[03E7C5B0:01CAA415] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 965 Lines: 24 On Tue, 2010-02-02 at 13:36 +0000, Ming Lei wrote: > 2010/2/2 Catalin Marinas : > > > In the iSCSI case, does the HCD driver write directly to a page cache > > page? Or it just fills in network packets that are copied to page cache > > pages by the iSCSI code (sorry, I'm not familiar with this part of the > > kernel). If the latter, the cache flushing in the HCD driver would not > > help and it needs to be done in the iSCSI code. > > So we should flush dcache page in the place where the user mapped > page is copied to, instead of low level driver which does not do such > thing always. Or both if you can't be sure whether the driver copies directly to a page cache page. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/