From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755867Ab2HVDnO (ORCPT ); Tue, 21 Aug 2012 23:43:14 -0400 Received: from mga02.intel.com ([134.134.136.20]:60843 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755386Ab2HVDnL (ORCPT ); Tue, 21 Aug 2012 23:43:11 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,807,1336374000"; d="scan'208";a="183788597" Subject: Re: [PATCH v2 3/3] spi: spi-davinci: convert to DMA engine API From: Vinod Koul To: Matt Porter Cc: cjb@laptop.org, grant.likely@secretlab.ca, Linux DaVinci Kernel List , Sekhar Nori , Linux MMC List , Linux Kernel Mailing List , Linux SPI Devel List , Linux ARM Kernel List In-Reply-To: <1345574589-24757-4-git-send-email-mporter@ti.com> References: <1345574589-24757-1-git-send-email-mporter@ti.com> <1345574589-24757-4-git-send-email-mporter@ti.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 22 Aug 2012 09:15:22 +0530 Message-ID: <1345607122.1895.44.camel@vkoul-udesk3> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2012-08-21 at 14:43 -0400, Matt Porter wrote: > Removes use of the DaVinci EDMA private DMA API and replaces > it with use of the DMA engine API. > > Signed-off-by: Matt Porter > --- > + struct dma_slave_config dma_rx_conf = { > + .direction = DMA_DEV_TO_MEM, > + .src_addr = (unsigned long)dspi->pbase + SPIBUF, > + .src_addr_width = data_type, > + .src_maxburst = 1, what does 1 mean in this context? We define as number of units that needs to be transfered, so are you sure that you want only one unit to be dma'ed in a single burst. that seems like killing your dmac, shouldn't you be using larger bursts for a better dma performance? -- ~Vinod