From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759426AbXLUKng (ORCPT ); Fri, 21 Dec 2007 05:43:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753506AbXLUKn2 (ORCPT ); Fri, 21 Dec 2007 05:43:28 -0500 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:49641 "EHLO the-village.bc.nu" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751393AbXLUKn1 (ORCPT ); Fri, 21 Dec 2007 05:43:27 -0500 Date: Fri, 21 Dec 2007 10:33:26 +0000 From: Alan Cox To: Benjamin Herrenschmidt Cc: , Andrew Morton , , , , , , Subject: Re: [PATCH 2/2] scsi: Use new __dma_buffer to align sense buffer in scsi_cmnd Message-ID: <20071221103326.7ce1bc4f@the-village.bc.nu> In-Reply-To: <20071221023011.4C4BADDDFA@ozlabs.org> References: <20071221023011.4C4BADDDFA@ozlabs.org> X-Mailer: Claws Mail 2.10.0 (GTK+ 2.10.14; i386-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 21 Dec 2007 13:30:08 +1100 Benjamin Herrenschmidt wrote: > The sense buffer ins scsi_cmnd can nowadays be DMA'ed into directly > by some low level drivers (that typically happens with USB mass > storage). Should that not be fixed in USB storage by using pci_alloc_coherent on the PCI device of the hub not peeing directly into kernel space ? It's also incomplete as a fix because I don't see what guarantees the buffer size will always exceed cache line size Alan