From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH] [3/22] Remove unchecked_isa_dma in advansys.c Date: Tue, 26 Feb 2008 04:44:02 +0100 Message-ID: <20080226034402.GD21577@one.firstfloor.org> References: <200802251235.889863872@firstfloor.org> <20080224233516.0657F1B4183@basil.firstfloor.org> <20080225214746.GA11382@parisc-linux.org> <20080225224035.GB21577@one.firstfloor.org> <20080225225022.GD20273@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from one.firstfloor.org ([213.235.205.2]:45438 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755254AbYBZDnZ (ORCPT ); Mon, 25 Feb 2008 22:43:25 -0500 Content-Disposition: inline In-Reply-To: <20080225225022.GD20273@parisc-linux.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthew Wilcox Cc: Andi Kleen , linux-scsi@vger.kernel.org, James.Bottomley@HansenPartnership.com On Mon, Feb 25, 2008 at 03:50:22PM -0700, Matthew Wilcox wrote: > On Mon, Feb 25, 2008 at 11:40:35PM +0100, Andi Kleen wrote: > > > (I must have fixed it somehow because it works on parisc, which is most > > > unforgiving of drivers which do DMA without the DMA API). > > > > At least on x86 the DMA API cannot do ISA bouncing. > > You're saying that if I set a 24-bit DMA mask, and then do a > pci_alloc_coherent(), x86 might hand me back something that's not > accessible? That would be just broken. No pci_alloc_coherent works, but pci_map_* will not. -Andi