From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932458Ab0CaQhe (ORCPT ); Wed, 31 Mar 2010 12:37:34 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:38745 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932271Ab0CaQha convert rfc822-to-8bit (ORCPT ); Wed, 31 Mar 2010 12:37:30 -0400 From: "Madhusudhan" To: "'kishore kadiyala'" , "'Vimal Singh'" Cc: , , , , References: <35697.192.168.10.89.1265898023.squirrel@dbdmail.itg.ti.com> <004701caab40$68b576e0$544ff780@am.dhcp.ti.com> Subject: RE: [PATCH-V2] OMAP: Fix for bus width which improves SD card's peformance. Date: Wed, 31 Mar 2010 11:37:19 -0500 Message-ID: <003b01cad0f0$6ea78040$544ff780@am.dhcp.ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcrQoDZtgS7R9HtfT3y08FTZG85QpAAT81gg In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: kishore kadiyala [mailto:kishorek.kadiyala@gmail.com] > Sent: Wednesday, March 31, 2010 2:03 AM > To: Vimal Singh > Cc: Madhusudhan; tony@atomide.com; svenkatr@ti.com; linux- > omap@vger.kernel.org; linux-kernel@vger.kernel.org; > jarkko.lavinen@nokia.com > Subject: Re: [PATCH-V2] OMAP: Fix for bus width which improves SD card's > peformance. > > Sorry for that and here's the Updated one. > > From: Kishore Kadiyala > > This patch improves low speeds for SD cards. > OMAP-MMC controller's can support maximum bus width of '8'. > when bus width is mentioned as "8" in controller data,the SD > stack will check whether bus width is "4" and if not it will > set bus width to "1" and there by degrading performance. > This patch fixes the issue and improves the performance of > SD cards. > > Signed-off-by: Kishore Kadiyala > Signed-off-by: Venkatraman S > Acked-by: Madhusudhan Chikkature > > --- > In V2 : Appended Signed-off by Venkat and Ack by Madhu > > Here are my experiment numbers, on a Class 6 SDHC card: > Read peformance is increased by 220% > Write Performance is increased by 52% > > drivers/mmc/host/omap_hsmmc.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > index 83f0aff..8c97c22 100644 > --- a/drivers/mmc/host/omap_hsmmc.c > +++ b/drivers/mmc/host/omap_hsmmc.c > @@ -2092,7 +2092,7 @@ static int __init omap_hsmmc_probe(struct > MMC_CAP_WAIT_WHILE_BUSY; > > if (mmc_slot(host).wires >= 8) > - mmc->caps |= MMC_CAP_8_BIT_DATA; > + mmc->caps |= (MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA); > else if (mmc_slot(host).wires >= 4) > mmc->caps |= MMC_CAP_4_BIT_DATA; > Kishore, Since this patch is not yet pushed it makes sense to fix the readability issue. Since 8-bit is the max how about:        if (mmc_slot(host).wires == 8)                mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA;        if (mmc_slot(host).wires == 4)                mmc->caps |= MMC_CAP_4_BIT_DATA; This would be little easy to read the code. Can you please repost the patch?? Regards, Madhu > -- > 1.6.3.3