From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760202AbaGYKpy (ORCPT ); Fri, 25 Jul 2014 06:45:54 -0400 Received: from mga02.intel.com ([134.134.136.20]:5329 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760101AbaGYKpw (ORCPT ); Fri, 25 Jul 2014 06:45:52 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,730,1400050800"; d="scan'208";a="548916533" Message-ID: <1406285147.8530.13.camel@smile.fi.intel.com> Subject: Re: [PATCH] spi/pxa2xx-pci: Enable DMA binding through device name From: Andy Shevchenko To: Arnd Bergmann Cc: Mika Westerberg , linux-arm-kernel@lists.infradead.org, Kweh Hock Leong , Eric Miao , Russell King , Haojian Zhuang , Mark Brown , Chew Chiau Ee , Darren Hart , chiauee85@gmail.com, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org Date: Fri, 25 Jul 2014 13:45:47 +0300 In-Reply-To: <5426556.OzZIXLrofJ@wuerfel> References: <1406196111-22861-1-git-send-email-hock.leong.kweh@intel.com> <20140725090714.GY1857@lahna.fi.intel.com> <20140725095559.GA1857@lahna.fi.intel.com> <5426556.OzZIXLrofJ@wuerfel> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.2-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2014-07-25 at 12:19 +0200, Arnd Bergmann wrote: > On Friday 25 July 2014 12:55:59 Mika Westerberg wrote: > > On Fri, Jul 25, 2014 at 12:07:14PM +0300, Mika Westerberg wrote: > > > On Fri, Jul 25, 2014 at 10:38:36AM +0200, Arnd Bergmann wrote: > > > > On Friday 25 July 2014 11:22:49 Mika Westerberg wrote: [] > > Something like this? Arnd, this dependency to certain DMA driver looks really bad. If we go that way, can we split that part to [another] module and make it dependent to DW_DMAC? Or shall we introduce a dmaengine type field in the platform data and dynamically choose proper filter-whatever-function to get the channel? > > Hock Leong / Chiaue Ee, are you able to check if this works on your BYT > > machines? > What I think you got wrong here (by following my bad advice) is the master > number. Looking at the code for dw_dma, I think src_master needs to be '1' > for your driver. On some SoCs we have up to 4 masters. It's blurry for me how the SPI should choose those masters. Currently it works fine, but I suspect there are [might be] performance issues. What about AVR32 case? We have to fix drivers as well there. > the dw_dma driver can be simplified a little by removing the special > case for the request line setting. Yes, this part I like. -- Andy Shevchenko Intel Finland Oy