Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753214AbYLALfF (ORCPT ); Mon, 1 Dec 2008 06:35:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751489AbYLALey (ORCPT ); Mon, 1 Dec 2008 06:34:54 -0500 Received: from 8bytes.org ([88.198.83.132]:45239 "EHLO 8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751446AbYLALey (ORCPT ); Mon, 1 Dec 2008 06:34:54 -0500 Date: Mon, 1 Dec 2008 12:34:51 +0100 From: Joerg Roedel To: Thomas Bogendoerfer Cc: linux-kernel@vger.kernel.org, mingo@elte.hu Subject: Re: [PATCH v3] Fix dma_mapping_error for 32bit x86 Message-ID: <20081201113451.GA24323@8bytes.org> References: <20081129124627.F2ABDFA8C8@solo.franken.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081129124627.F2ABDFA8C8@solo.franken.de> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1964 Lines: 46 On Sat, Nov 29, 2008 at 01:46:27PM +0100, Thomas Bogendoerfer wrote: > Devices like b44 ethernet can't dma from addresses above 1GB. The driver > handles this cases by falling back to GFP_DMA allocation. But for detecting > the problem it needs to get an indication from dma_mapping_error. > The bug is triggered by using a VMSPLIT option of 2G/2G. Looks like your system uses swiotlb as the dma_ops backend. Its the only implementation providing the ops->mapping_error callback and does not use bad_dma_address as the error value. > Signed-off-by: Thomas Bogendoerfer Acked-by: Joerg Roedel > > diff -ru orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h linux-2.6.27.4/include/asm-x86/dma-mapping.h > --- orig/linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 00:05:07.000000000 +0200 > +++ linux-2.6.27.4/include/asm-x86/dma-mapping.h 2008-10-26 11:06:14.000000000 +0100 > @@ -74,15 +74,13 @@ > /* Make sure we keep the same behaviour */ > static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr) > { > -#ifdef CONFIG_X86_32 > - return 0; > -#else > +#ifdef CONFIG_X86_64 > struct dma_mapping_ops *ops = get_dma_ops(dev); > if (ops->mapping_error) > return ops->mapping_error(dev, dma_addr); > > - return (dma_addr == bad_dma_address); > #endif > + return (dma_addr == bad_dma_address); > } > > #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f) > -- > 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/ -- 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/