Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966392Ab0BZWAU (ORCPT ); Fri, 26 Feb 2010 17:00:20 -0500 Received: from gate.crashing.org ([63.228.1.57]:56052 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966380Ab0BZWAI (ORCPT ); Fri, 26 Feb 2010 17:00:08 -0500 Subject: Re: USB mass storage and ARM cache coherency From: Benjamin Herrenschmidt To: Catalin Marinas Cc: Alan Stern , Matthew Dharm , linux-usb@vger.kernel.org, Russell King - ARM Linux , "Mankad,Maulik Ojas" , Sergei Shtylyov , Ming Lei , Sebastian Siewior , Oliver Neukum , linux-kernel , "Shilimkar,Santosh" , Pavel Machek , Greg KH , linux-arm-kernel , James Bottomley In-Reply-To: <1267200044.14703.31.camel@e102109-lin.cambridge.arm.com> References: <1267046036.23523.1693.camel@pasglop> <1267200044.14703.31.camel@e102109-lin.cambridge.arm.com> Content-Type: text/plain; charset="UTF-8" Date: Sat, 27 Feb 2010 08:36:03 +1100 Message-ID: <1267220163.23523.1806.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1085 Lines: 35 On Fri, 2010-02-26 at 16:00 +0000, Catalin Marinas wrote: > > I'm surprised that usb-storage has an issue here. It shouldn't > afaik, > > since it's just a SCSI driver (or not anymore ?) and the BIO or > > filesystems handle things there no ? I haven't seen a single call to > > flush_dcache_page() in any of drivers/scsi, drivers/ata or > drivers/ide > > when I looked... > > The BIO or filesystem code don't call flush_dcache_page() either (well > some do like cramfs or jffs but they decompress the data received from > the block device). That's weird... that would mean that all existing PIO IDE or SCSI is broken etc... Including I$/D$ cache coherency on powerpc and more. That surprises me :-) On an older kernel tree here: $ grep -r flush_dcache_page fs | wc -l 118 So maybe that's where things need fixing ? Cheers, Ben. -- 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/