Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759316AbYFZOSo (ORCPT ); Thu, 26 Jun 2008 10:18:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755042AbYFZOSc (ORCPT ); Thu, 26 Jun 2008 10:18:32 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:38177 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756309AbYFZOSb (ORCPT ); Thu, 26 Jun 2008 10:18:31 -0400 Date: Thu, 26 Jun 2008 10:18:30 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Jens Axboe cc: FUJITA Tomonori , , , , Subject: Re: Scatter-gather list constraints In-Reply-To: <20080626063559.GJ20851@kernel.dk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1024 Lines: 22 On Thu, 26 Jun 2008, Jens Axboe wrote: > I don't think adding anything in the general IO path makes a lot of > sense, this is a really screwy case. I don't mind adding work-arounds to > the block layer to cater for hardware weirdness, but this is getting a > little silly. We could provide a helper function for 'bouncing' this > request and thus reuse the block bounce buffer for this, but I'm not > even sure how to simply express this generically. As it is likely of no > use outside of this specific case, putting it in the driver (or usb > layer, if you expect more of these similar cases) is the best option. That sounds great. If any of you could provide the bounce-buffer helper functions, I will be pleased to write the USB-specific code to call them. Alan Stern -- 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/