From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrei Warkentin Subject: Re: [PATCH] mmc: sdhci: add support for pre_req and post_req Date: Sat, 16 Apr 2011 18:06:00 -0500 Message-ID: References: <1302116833-24540-1-git-send-email-per.forlin@linaro.org> <1302972516-8673-1-git-send-email-shawn.guo@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from exprod5og115.obsmtp.com ([64.18.0.246]:37277 "EHLO exprod5og115.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754347Ab1DPXGD convert rfc822-to-8bit (ORCPT ); Sat, 16 Apr 2011 19:06:03 -0400 Received: from il93mgrg01.am.mot-mobility.com ([10.22.94.168]) by il93mgrg01.am.mot-mobility.com (8.14.3/8.14.3) with ESMTP id p3GN4AAV011602 for ; Sat, 16 Apr 2011 19:04:10 -0400 (EDT) Received: from mail-wy0-f170.google.com (mail-wy0-f170.google.com [74.125.82.170]) by il93mgrg01.am.mot-mobility.com (8.14.3/8.14.3) with ESMTP id p3GN2jnI011132 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Sat, 16 Apr 2011 19:04:10 -0400 (EDT) Received: by mail-wy0-f170.google.com with SMTP id 34so5175435wyb.15 for ; Sat, 16 Apr 2011 16:06:00 -0700 (PDT) In-Reply-To: <1302972516-8673-1-git-send-email-shawn.guo@linaro.org> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Shawn Guo Cc: linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, patches@linaro.org, cjb@laptop.org, per.forlin@linaro.org Hi Shawn, On Sat, Apr 16, 2011 at 11:48 AM, Shawn Guo wrot= e: > pre_req() runs dma_map_sg() post_req() runs dma_unmap_sg. > If not calling pre_req() before sdhci_request(), request() > will prepare the cache just like it did it before. > It is optional to use pre_req() and post_req(). > > Signed-off-by: Shawn Guo > --- > I worked out the patch by referring to Per's patch below. > > =A0omap_hsmmc: add support for pre_req and post_req > > It adds pre_req and post_req support for sdhci based host drivers to > work with Per's non-blocking optimization. =A0But I only have imx esd= hc > based hardware to test. =A0Unfortunately, I can not measure the > performance gain using mmc_test, because the current esdhc driver on > mainline fails on the test. =A0So I just did a quick test using 'dd', > but sadly, I did not see noticeable performance gain here. =A0The > followings are possible reasons I can think of right away. > > * The patch did not add pre_req and post_req correctly. =A0Please hel= p > =A0review to catch the mistakes if any. > * The imx esdhc driver uses SDHCI_SDMA (max_segs is 1) than SDHCI_ADA= M > =A0(max_segs is 128), due to the broken ADMA support on imx esdhc. =A0= So > =A0can people holding other sdhci based hardware give a try on the > =A0patch? > > Hopefully, I can find some time to have a close look at the mmc_test > failure and the broken ADMA with imx esdhc. > I'll try it out... A