Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752205AbbESWJx (ORCPT ); Tue, 19 May 2015 18:09:53 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:58091 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751911AbbESWJq (ORCPT ); Tue, 19 May 2015 18:09:46 -0400 Date: Tue, 19 May 2015 23:09:36 +0100 From: Russell King - ARM Linux To: Lorenzo Nava Cc: Catalin Marinas , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] arm: DMA-API contiguous cacheable memory Message-ID: <20150519220936.GL2067@n2100.arm.linux.org.uk> References: <20150519163436.GZ21251@e104818-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 797 Lines: 17 On Wed, May 20, 2015 at 12:05:54AM +0200, Lorenzo Nava wrote: > Maybe my interpretation of dma_alloc_coherent() is not correct, and > the coherency can be managed using the dma_sync_single_for_* functions > and it doesn't require hardware mechanism. dma_sync_single_for_* are only for use with the streaming DMA API, where you must have already mapped the buffer using one of the dma_map_* functions. Anything other than that is abusing the API. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/