From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757033Ab3ANPiH (ORCPT ); Mon, 14 Jan 2013 10:38:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:3795 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756545Ab3ANPiE (ORCPT ); Mon, 14 Jan 2013 10:38:04 -0500 Message-ID: <1358177872.4357.53.camel@t520.localdomain> Subject: Re: [Linux-c6x-dev] [PATCH 3/9] c6x: Provide dma_mmap_coherent() and dma_get_sgtable() From: Mark Salter To: Geert Uytterhoeven Cc: linux-arch@vger.kernel.org, linux-c6x-dev@linux-c6x.org, linux-kernel@vger.kernel.org, Marek Szyprowski Date: Mon, 14 Jan 2013 10:37:52 -0500 In-Reply-To: <1358073890-3610-3-git-send-email-geert@linux-m68k.org> References: <1358073890-3610-1-git-send-email-geert@linux-m68k.org> <1358073890-3610-3-git-send-email-geert@linux-m68k.org> Organization: Red Hat, Inc Content-Type: text/plain; charset="iso-8859-7" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2013-01-13 at 11:44 +0100, Geert Uytterhoeven wrote: > c6x/allmodconfig (assumed): > > drivers/media/v4l2-core/videobuf2-dma-contig.c: In function ¡vb2_dc_mmap¢: > drivers/media/v4l2-core/videobuf2-dma-contig.c:204: error: implicit declaration of function ¡dma_mmap_coherent¢ > drivers/media/v4l2-core/videobuf2-dma-contig.c: In function ¡vb2_dc_get_base_sgt¢: > drivers/media/v4l2-core/videobuf2-dma-contig.c:387: error: implicit declaration of function ¡dma_get_sgtable¢ > > For architectures using dma_map_ops, dma_mmap_coherent() and > dma_get_sgtable() are provided in . > > C6x does not use dma_map_ops, hence it should implement them as inline > stubs using dma_common_mmap() and dma_common_get_sgtable(). > So are dma_mmap_coherent() and dma_get_sgtable() part of the DMA API now? I don't them in Documentation/DMA*.txt anywhere. Why does the default dma_common_mmap() for !CONFIG_MMU return an error? Wouldn't it be better to provide default implementations that an arch could override rather than having to patch all "no dma_map_ops" architectures? --Mark