From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756906AbcJ3SRg (ORCPT ); Sun, 30 Oct 2016 14:17:36 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:36633 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750942AbcJ3SRf (ORCPT ); Sun, 30 Oct 2016 14:17:35 -0400 Message-ID: <58163939.40404@gmail.com> Date: Sun, 30 Oct 2016 23:47:29 +0530 From: Sudip Mukherjee User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Andrew Morton CC: linux-kernel@vger.kernel.org, fengguang.wu@intel.com Subject: Re: [PATCH] m32r: add simple dma References: <1475949198-31623-1-git-send-email-sudipm.mukherjee@gmail.com> <20161020202918.b7cb3fe24058addddabb7534@linux-foundation.org> In-Reply-To: <20161020202918.b7cb3fe24058addddabb7534@linux-foundation.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andrew, On Friday 21 October 2016 08:59 AM, Andrew Morton wrote: > On Sat, 8 Oct 2016 23:23:18 +0530 Sudip Mukherjee wrote: > >> Some builds of m32r were failing as it tried to build few drivers which >> needed dma but m32r is not having dma support. Objections were raised >> when it was tried to make those drivers depend on HAS_DMA. > > Huh. What were these objections? That sounds like the appropriate > fix. And I suggest that a summary of those objections be captured in > this patch's changelog. Sorry for the delay in reply. Got busy in dayjob and relocation. I was asked to provide dma stubs instead of adding HAS_DMA in the Kconfig. http://www.spinics.net/lists/kernel/msg2277152.html And an old thread- http://www.spinics.net/lists/alsa-devel/msg50931.html It appeared to me that instead of adding dma stubs and returning error values from them it will be better to add dma_noop to m32r. Looking at the simplicity of dma_noop it seems that it should work. What will you suggest? Do i send v2 after adding the "dma stub" comment and the link to the thread in the commit message or should I opt for dma stub? > >> So the next >> best thing is to add dma support to m32r. >> dma_noop is a very simple dma with 1:1 memory mapping. >> >> Signed-off-by: Sudip Mukherjee >> --- >> >> Hi Andrew, >> Just to let you know that this was not tested on any board. I think I >> have told you earlier that inspite of all my efforts I could not find >> any source of information to procure a board of m32r. > > It is a worry. We're saying "m32r linux now supports these drivers", > only we don't know if that is true. FYI, I tried to contact Renesas for m32r boards and this is the reply I received (Dated- Jan 20, 2016): " Hi Sudip-san, I’m afraid but I don’t know about m32r. Also I searched our private web site, I could not find usuful information about m32r… Best regards, Yoshihiro Shimoda " Regards Sudip