From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 280DBC5CFE7 for ; Wed, 11 Jul 2018 12:17:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D85420852 for ; Wed, 11 Jul 2018 12:17:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="kQ0REPas" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D85420852 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732906AbeGKMVI (ORCPT ); Wed, 11 Jul 2018 08:21:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:58596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726587AbeGKMVH (ORCPT ); Wed, 11 Jul 2018 08:21:07 -0400 Received: from localhost (unknown [106.200.243.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6DFB72084A; Wed, 11 Jul 2018 12:17:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1531311424; bh=7MPLgS8jcq32VU6ZOl+aL6zKzSYkVQuVD8gwoppUNW0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kQ0REPasqeQ6hjZSrqYY4mTMwfHtAXyuhNc3dtssPMClTTRZnlrxD0VEIdWJurI/a 4qZI8tD1eQRNsOSnUgnNbpMz5e2Gh4cf34v7V5ZW+azYG7PpW4NtNRrUcBWlWsQVee dWOz/5r49HY+PVbQDOGAQ6p205q8CI0TuXYMUDKw= Date: Wed, 11 Jul 2018 17:46:55 +0530 From: Vinod To: Paul Cercueil Cc: Rob Herring , Mark Rutland , Ralf Baechle , Paul Burton , James Hogan , Zubair Lutfullah Kakakhel , Mathieu Malaterre , Daniel Silsby , dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org Subject: Re: [PATCH 02/14] dmaengine: dma-jz4780: Separate chan/ctrl registers Message-ID: <20180711121655.GS3219@vkoul-mobl> References: <20180703123214.23090-1-paul@crapouillou.net> <20180703123214.23090-3-paul@crapouillou.net> <20180709170359.GI22377@vkoul-mobl> <1531237019.17118.1@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1531237019.17118.1@crapouillou.net> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10-07-18, 17:36, Paul Cercueil wrote: > > > @@ -3,7 +3,8 @@ > > > Required properties: > > > > > > - compatible: Should be "ingenic,jz4780-dma" > > > -- reg: Should contain the DMA controller registers location and > > > length. > > > +- reg: Should contain the DMA channel registers location and > > > length, followed > > > + by the DMA controller registers location and length. > > > - interrupts: Should contain the interrupt specifier of the DMA > > > controller. > > > - interrupt-parent: Should be the phandle of the interrupt > > > controller that > > > - clocks: Should contain a clock specifier for the JZ4780 PDMA > > > clock. > > > @@ -22,7 +23,8 @@ Example: > > > > > > dma: dma@13420000 { > > > compatible = "ingenic,jz4780-dma"; > > > - reg = <0x13420000 0x10000>; > > > + reg = <0x13420000 0x400 > > > + 0x13421000 0x40>; > > > > Second should be optional or we break platform which may not have > > updated DT.. > > See comment below. > > > > - jzdma->base = devm_ioremap_resource(dev, res); > > > - if (IS_ERR(jzdma->base)) > > > - return PTR_ERR(jzdma->base); > > > + jzdma->chn_base = devm_ioremap_resource(dev, res); > > > + if (IS_ERR(jzdma->chn_base)) > > > + return PTR_ERR(jzdma->chn_base); > > > + > > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); > > > + if (!res) { > > > + dev_err(dev, "failed to get I/O memory\n"); > > > + return -EINVAL; > > > + } > > > > okay and this breaks if you happen to get probed on older DT. I think DT > > is treated as ABI so you need to continue support older method while > > finding if DT has split resources > > See my response to PrasannaKumar. All the Ingenic-based boards do compile > the devicetree within the kernel, so I think it's still fine to add breaking > changes. I'll wait on @Rob to give his point of view on this, though. > > (It's not something hard to change, but I'd like to know what's the policy > in that case. I have other DT-breaking patches to submit) The policy is that DT is an ABI and should not break :) Who maintains Ingenic arch. MAINTAINERS doesn't tell me. -- ~Vinod