From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754127Ab2IQHcG (ORCPT ); Mon, 17 Sep 2012 03:32:06 -0400 Received: from void.printf.net ([89.145.121.20]:36176 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753870Ab2IQHcD (ORCPT ); Mon, 17 Sep 2012 03:32:03 -0400 From: Chris Ball To: Kyungsik Lee Cc: Venkatraman S , Jaehoon Chung , Adrian Hunter , Philip Rakity , raphael.andy.lee@gmail.com, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RESEND v6] mmc: core: Remove bounce buffer in mmc_send_cxd_data() References: <1343955483-6917-1-git-send-email-kyungsik.lee@lge.com> Date: Mon, 17 Sep 2012 03:32:12 -0400 In-Reply-To: <1343955483-6917-1-git-send-email-kyungsik.lee@lge.com> (Kyungsik Lee's message of "Fri, 3 Aug 2012 09:58:03 +0900") Message-ID: User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.1.90 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Thu, Aug 02 2012, Kyungsik Lee wrote: > It is expected that Extended CSD register(the size of this register > is larger than CID/CSD) will be referenced more frequently as more > fields have been added to Extended CSD and it seems that it is not > a good option to double the memory used. > > This patch is intended to avoid the use of bounce buffer for reading > Extended CSD register in mmc_send_cxd_data(). It will provide a better > performance gain by removing memcpy() overhead for a half KiB and > a redundant bounce buffer allocated repeatedly at the cost of providing > DMA-capable buffer from upper caller(but on-stack buffer is allowed > with no performance gain). > > Signed-off-by: Kyungsik Lee > Reviewed-by: Venkatraman S Thanks, pushed to mmc-next for 3.7. - Chris. -- Chris Ball One Laptop Per Child