From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755187Ab1JKQxc (ORCPT ); Tue, 11 Oct 2011 12:53:32 -0400 Received: from mga02.intel.com ([134.134.136.20]:59846 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754035Ab1JKQxb (ORCPT ); Tue, 11 Oct 2011 12:53:31 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,351,1309762800"; d="scan'208";a="62186068" Subject: Re: [PATCHv4] DMAEngine: Define interleaved transfer request api From: Vinod Koul To: Jassi Brar Cc: "Williams, Dan J" , Russell King , Barry Song <21cnbao@gmail.com>, linux-kernel@vger.kernel.org, DL-SHA-WorkGroupLinux , Dave Jiang In-Reply-To: References: <1317191992-3635-1-git-send-email-jaswinder.singh@linaro.org> <1317200618.1573.1765.camel@vkoul-udesk3> <1317295068.1573.1780.camel@vkoul-udesk3> <20111003161349.GB28287@flint.arm.linux.org.uk> <1317966346.1573.2252.camel@vkoul-udesk3> <1317997177.1573.2275.camel@vkoul-udesk3> <1318229592.1573.2298.camel@vkoul-udesk3> <1318238296.1546.3.camel@vkoul-udesk3> <1318243501.1546.12.camel@vkoul-udesk3> <1318262559.1546.31.camel@vkoul-udesk3> <1318334185.1546.344.camel@vkoul-udesk3> Content-Type: text/plain; charset="UTF-8" Date: Tue, 11 Oct 2011 22:15:37 +0530 Message-ID: <1318351537.1546.356.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, 2011-10-11 at 21:27 +0530, Jassi Brar wrote: > On 11 October 2011 17:26, Vinod Koul wrote: > >> >> > > >> >> > But I am fine if we find a common ground and merge the two where dmac > >> >> > can cleanly identify direction and mode it is operating. > >> >> > > >> >> The client would set the xfer_direction and dmac would interpret as > >> >> > >> >> enum xfer_direction { > >> >> MEM_TO_MEM, -> Async/Memcpy mode > >> >> MEM_TO_DEV, -> Slave mode & From Memory to Device > >> >> DEV_TO_MEM, -> Slave mode & From Device to Memory > >> >> DEV_TO_DEV, -> Slave mode & From Device to Device > >> >> } > >> >> > >> >> How could it get any cleaner? > >> > Consider the case of a dmac driver which supports interleaved dma as > >> > well as memcpy and slave > >> > It needs to interpret dma_data_direction for later cases and > >> > xfer_direction for former ones. > >> dma_data_direction is the mapping attribute of a buffer and is not meant to > >> tell type of source and destination of a transfer. > >> xfer_direction is meant for that purpose. > >> So I'd rather convert device_prep_dma_cyclic and device_prep_slave_sg > >> to use xfer_direction. > > > > If the conversion id done for all drivers, then it should be fine... > > > I already said that many days ago. Though I am not sure what blocks > this patch if that conversion is done separately (which would touch many > subsystems). For this patchset, you need to remove frm_irq in template -- ~Vinod