From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753675AbaIOQcd (ORCPT ); Mon, 15 Sep 2014 12:32:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13186 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752769AbaIOQcc (ORCPT ); Mon, 15 Sep 2014 12:32:32 -0400 Message-ID: <54171485.5010803@redhat.com> Date: Mon, 15 Sep 2014 12:32:05 -0400 From: Jon Masters Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Catalin Marinas CC: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: "dma-coherent" property inheritance (arm vs arm64) References: <5414FF8F.5040409@redhat.com> <20140915155216.GG5415@arm.com> In-Reply-To: <20140915155216.GG5415@arm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/15/2014 11:52 AM, Catalin Marinas wrote: > Hi Jon, > > On Sun, Sep 14, 2014 at 03:38:07AM +0100, Jon Masters wrote: >> commit 6ecba8eb51b7d23fda66388a5420be7d8688b186 >> Author: Catalin Marinas >> Date: Fri Apr 25 15:31:45 2014 +0100 >> >> arm64: Use bus notifiers to set per-device coherent DMA ops >> >> Thus at this point, on 32-bit systems, we have defined this function: >> >> set_arch_dma_coherent_ops > > It was a timing issue that they are not in sync. I would have used > set_arch_dma_coherent_ops() but it wasn't very clear when it gets merged > and changing the default on arm64 broke some other assumptions, so a > temporary fix. Ok. So arm64 will automatically switch over to set_arch_dma_coherent_ops (once it's there, it will be called automatically anyway because it's in the callchain anyway already). For the moment, on our internal PCI trees, we'll add a notifier and wait for upstream to get PCI support and figure this out as part of that activity. In the case of ACPI, I'm still pushing for _CCA methods to be added by default because it makes sense to be verbose in describing platform hardware devices, even in spite of default. Jon.