Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754796Ab0BHKDT (ORCPT ); Mon, 8 Feb 2010 05:03:19 -0500 Received: from mail-ew0-f228.google.com ([209.85.219.228]:36830 "EHLO mail-ew0-f228.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751797Ab0BHKDS (ORCPT ); Mon, 8 Feb 2010 05:03:18 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=Ki5g4NQC6XkVsSlu+MnXoOiDupKUe6Oik+8oWzytryb64+yBSChn6jBGaXKza47zOJ iRy8YYglUFaZ1/FPry6xXsMhqt6DLQVZcJ/MLMMp9elxC83UAzJNv3rcdWAtvKavWXqg Y8TPgR6Pm5T8qI1HyUG28yaaM9gk3uH3UZbGY= Message-ID: <4B6FE162.6000004@warmcat.com> Date: Mon, 08 Feb 2010 11:03:14 +0100 From: Andy Green User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.7) Gecko/20100120 Fedora/3.0.1-1.fc13 Thunderbird/3.0.1 MIME-Version: 1.0 To: Catalin Marinas CC: Pavel Machek , Matthew Dharm , Sergei Shtylyov , Ming Lei , Sebastian Siewior , linux-usb@vger.kernel.org, linux-kernel , Greg KH , linux-arm-kernel Subject: Re: USB mass storage and ARM cache coherency References: <20100208065519.GE1290@ucw.cz> <1265622676.4020.19.camel@pc1117.cambridge.arm.com> In-Reply-To: <1265622676.4020.19.camel@pc1117.cambridge.arm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 796 Lines: 17 On 02/08/10 10:51, Somebody in the thread at some point said: > We could of course flush the caches every time we get a page fault but > that's far from optimal, especially since DMA-capable drivers to do not > pollute the D-cache and don't need this extra flushing. Note that the > recent ARM processors have PIPT caches but separate for I and D and it's > the PIO drivers that pollute the D-cache. Just noting that AFAIK iMX31 USB and MMC drivers both are PIO at the moment, for lack of any platform DMA support of its unusual DMA engine. -Andy -- 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/