Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754403Ab0H0A0r (ORCPT ); Thu, 26 Aug 2010 20:26:47 -0400 Received: from sh.osrg.net ([192.16.179.4]:46965 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752690Ab0H0A0o (ORCPT ); Thu, 26 Aug 2010 20:26:44 -0400 Date: Fri, 27 Aug 2010 09:26:17 +0900 To: khc@pm.waw.pl Cc: fujita.tomonori@lab.ntt.co.jp, benh@kernel.crashing.org, linux@arm.linux.org.uk, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: ARM: 2.6.3[45] PCI regression (IXP4xx and PXA?) From: FUJITA Tomonori In-Reply-To: References: <1282254713.22370.368.camel@pasglop> <20100826205344E.fujita.tomonori@lab.ntt.co.jp> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20100827092453A.fujita.tomonori@lab.ntt.co.jp> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (sh.osrg.net [192.16.179.4]); Fri, 27 Aug 2010 09:26:19 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 891 Lines: 16 On Thu, 26 Aug 2010 18:02:46 +0200 Krzysztof Halasa wrote: > FUJITA Tomonori writes: > > > Lots of drivers call dma_set_coherent_mask with 64bit mask and then > > call it with 32bit mask if 64bit mask fails. > > Which seems strange to me. If the driver asks for 64-bit mask and the > system can only give it 32-bits, why return an error? Every 32-bit > address is also 64-bit, with the most significant bits simply cleared. As I wrote, the DMA API simply wasn't designed in that way (let architectures to clip the mask), I guess. If it was, dma_set_coherent_mask might return the actual mask. -- 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/