From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758746AbaGXDgj (ORCPT ); Wed, 23 Jul 2014 23:36:39 -0400 Received: from mail-bl2lp0210.outbound.protection.outlook.com ([207.46.163.210]:12508 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758526AbaGXDgh convert rfc822-to-8bit (ORCPT ); Wed, 23 Jul 2014 23:36:37 -0400 From: Yao Yuan To: Marek Vasut CC: "wsa@the-dreams.de" , "mark.rutland@arm.com" , "shawn.guo@linaro.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-i2c@vger.kernel.org" Subject: RE: [PATCH v5 0/2] i2c: add DMA support for freescale i2c driver Thread-Topic: [PATCH v5 0/2] i2c: add DMA support for freescale i2c driver Thread-Index: AQHPplZS12HOgaurWE6pPVifgTUu7ZutlmmAgADwPgA= Date: Thu, 24 Jul 2014 03:36:34 +0000 Message-ID: References: <1406103883-3572-1-git-send-email-yao.yuan@freescale.com> <201407231428.01278.marex@denx.de> In-Reply-To: <201407231428.01278.marex@denx.de> Accept-Language: en-US, zh-CN Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [123.151.195.50] x-microsoft-antispam: BCL:0;PCL:0;RULEID: x-forefront-prvs: 028256169F x-forefront-antispam-report: SFV:NSPM;SFS:(6009001)(51704005)(24454002)(377454003)(199002)(189002)(74316001)(99396002)(21056001)(46102001)(79102001)(87936001)(64706001)(92566001)(83322001)(4396001)(85852003)(83072002)(2656002)(76576001)(85306003)(50986999)(101416001)(54356999)(105586002)(77982001)(107046002)(20776003)(81542001)(76482001)(80022001)(99286002)(66066001)(33646002)(81342001)(106116001)(74502001)(76176999)(31966008)(106356001)(95666004)(110136001)(86362001)(74662001)(108616002)(24736002);DIR:OUT;SFP:;SCL:1;SRVR:BL2PR03MB338;H:BL2PR03MB338.namprd03.prod.outlook.com;FPR:;MLV:sfv;PTR:InfoNoRecords;MX:1;LANG:en; Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Marek Vasut wrote: > On Wednesday, July 23, 2014 at 10:24:41 AM, Yuan Yao wrote: > > Changed in v5: > > - add "*chan_dev = dma->chan_using->device->dev" for reduce the call time. > > Did you check if the compiler generates different code ? > Sorry, I didn't compare the assembly code. It's a subtle change. As you mentioned the "noodle" before. Old: dma_map_single(dma->chan_using->device->dev, ...); dma_mapping_error(dma->chan_using->device->dev, ...); dma_unmap_single(dma->chan_using->device->dev, ...); New: struct device *chan_dev = dma->chan_using->device->dev; dma_map_single(chan_dev, ...); dma_mapping_error(chan_dev, ...); dma_unmap_single(chan_dev, ...); > > - add the test logs. > > [...] > > Best regards, > Marek Vasut