Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933999AbXHFXAn (ORCPT ); Mon, 6 Aug 2007 19:00:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765586AbXHFXAZ (ORCPT ); Mon, 6 Aug 2007 19:00:25 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:41912 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765419AbXHFXAX (ORCPT ); Mon, 6 Aug 2007 19:00:23 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Message-ID: <46B7A7E9.5080606@s5r6.in-berlin.de> Date: Tue, 07 Aug 2007 00:59:53 +0200 From: Stefan Richter User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.5) Gecko/20070804 SeaMonkey/1.1.3 MIME-Version: 1.0 To: Robert Hancock CC: Benjamin Herrenschmidt , Olaf Hering , linuxppc-dev@ozlabs.org, stable@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.22.y] ieee1394: revert "sbp2: enforce 32bit DMA mapping" References: <46B4B3DC.7020609@shaw.ca> <46B4B7C6.1040107@s5r6.in-berlin.de> <1186272926.938.8.camel@localhost.localdomain> <46B5824B.1000103@s5r6.in-berlin.de> <1186351473.938.21.camel@localhost.localdomain> <20070806135124.GA2900@suse.de> <1186436848.938.75.camel@localhost.localdomain> <46B79F25.50205@s5r6.in-berlin.de> <46B79FD7.9020801@shaw.ca> <1186439529.938.95.camel@localhost.localdomain> <46B7A22D.4030909@shaw.ca> In-Reply-To: <46B7A22D.4030909@shaw.ca> X-Enigmail-Version: 0.95.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1104 Lines: 27 Robert Hancock wrote: > I would agree, though, that sbp2 isn't really the place for setting > this, since the DMA mask is presently a property of the device, not of > the user.. The mask that sbp2 set was because sbp2 has (in theory, not yet in practice) a _narrower requirement on address ranges than the chip_ --- hence it has (in theory) a narrower requirement on DMA mappings than the ohci1394 driver has. That's because sbp2 uses the controller in a special mode, as a bus bridge. It is the only user of that feature among the higher-level IEEE 1394 drivers. No other IEEE 1394 application-layer software has this requirement. (Well, debugging and forensic tools rely on that mode too, notably BenH's firescope, but this software runs remote, hence it's a different beast from sbp2.) -- Stefan Richter -=====-=-=== =--- --=== http://arcgraph.de/sr/ - 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/