Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758694AbcCVMe3 (ORCPT ); Tue, 22 Mar 2016 08:34:29 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:51414 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756528AbcCVMeV (ORCPT ); Tue, 22 Mar 2016 08:34:21 -0400 Date: Tue, 22 Mar 2016 12:34:08 +0000 From: Russell King - ARM Linux To: Sodagudi Prasad Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, shashim@codeaurora.org, sboyd@codeaurora.org Subject: Re: [Query] doubt on parameters passed to dma_map_single_attrs() API Message-ID: <20160322123408.GN19428@n2100.arm.linux.org.uk> References: 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: 573 Lines: 17 On Tue, Mar 22, 2016 at 03:53:02PM +0530, Sodagudi Prasad wrote: > > Hi All, > > Would like to check whether the dma_map_single_attrs() API, can accept ptr > variable from high memory or not? It can't. Direct mapped, lowmem only. No pointers allowed from dma_alloc_coherent(), dma_alloc_writecombine(), ioremap(), vmalloc(), kmap(), kmap_atomic() or similar function, or derived from one of these. -- RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.