From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752970Ab3BUI3w (ORCPT ); Thu, 21 Feb 2013 03:29:52 -0500 Received: from smtp2.macqel.be ([194.78.208.39]:8550 "EHLO smtp2.macqel.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752734Ab3BUI3v (ORCPT ); Thu, 21 Feb 2013 03:29:51 -0500 Date: Thu, 21 Feb 2013 09:29:47 +0100 From: Philippe De Muyter To: Vinod Koul Cc: linux-kernel@vger.kernel.org, Greg Ungerer , Stany MARCEL , Dan Williams , Greg Kroah-Hartman Subject: Re: [PATCH resent] dma: add the freescale-provided MultiChannel DMA driver Message-ID: <20130221082947.GA8799@frolo.macqel> References: <1359999503-29215-1-git-send-email-phdm@macqel.be> <20130220063147.GD23302@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130220063147.GD23302@intel.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vinod, On Wed, Feb 20, 2013 at 12:01:47PM +0530, Vinod Koul wrote: > On Mon, Feb 04, 2013 at 06:38:23PM +0100, Philippe De Muyter wrote: > > This patch adds the (cleaned-up) Freescale-provided MultiChannel DMA > > driver for ColdFire M54xx and MPC8220 processors. > > > > This driver is needed for the ethernet FEC driver of the ColdFire > > M547x and M548x processors. > > > > It is not dmaengine-enabled, but that's not needed for the above FEC driver. > > I have however installed it in the driver/dma tree as this IP block is not > > m68k-specific, but freescale-specific, and shared at least between powerpc > > and coldfire parts (possibly arm-parts as well). > > > > The installation in drivers/dma implies a small rule change in > > drivers/Makefile to enter drivers/dma on CONFIG_DMADEVICES instead > > of CONFIG_DMAENGINE. > BIG NAK Thanks for your answer. > 1. Please run Checkpath and reread Documentation/CodingStyle, specfically CH4. > Avoid the CamelCase I had run checkpatch when I made the patch, but CamelCase was not yet searched for at that time. I will look at that. > 2. If you are not using dmaengine APIs then drivers/dma/ is not a place for you. What would be the place then for a multi-architecture dma driver. Freescale often reuses the same blocks for its m68k (coldfire), powerpc and arm (iMX) product lines. A dma driver with many similarities is already under the arch/powerpc subtree. I would like to avoid that, because it clearly hurts reusability. > 3. While glancing at the code, I dont see why you cant use dmaengine APIs? lack of need (the sole current user of this dma driver is a FEC ethernet driver which uses the current interface), time and expertise. but any help is welcome. > 4. lastly, am blown off by your own implementation of memcpy, WHY? Kernel is > smarter than you! I agree, but don't shoot the messenger. I am not the original author, this is freescale code. I only ensured that it compiles and works with current kernels, and suppressed many checkpatch warnings. Best regards Philippe