From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pd3mo1so.prod.shaw.ca (shawidc-mo1.cg.shawcable.net [24.71.223.10]) by ozlabs.org (Postfix) with ESMTP id 34E26DDECE for ; Tue, 7 Aug 2007 08:35:49 +1000 (EST) Received: from pd3mr4so.prod.shaw.ca (pd3mr4so-qfe3.prod.shaw.ca [10.0.141.180]) by l-daemon (Sun ONE Messaging Server 6.0 HotFix 1.01 (built Mar 15 2004)) with ESMTP id <0JMD00JIDIRJUL80@l-daemon> for linuxppc-dev@ozlabs.org; Mon, 06 Aug 2007 16:35:43 -0600 (MDT) Received: from pn2ml3so.prod.shaw.ca ([10.0.121.147]) by pd3mr4so.prod.shaw.ca (Sun Java System Messaging Server 6.2-7.05 (built Sep 5 2006)) with ESMTP id <0JMD008AKIRAZU10@pd3mr4so.prod.shaw.ca> for linuxppc-dev@ozlabs.org; Mon, 06 Aug 2007 16:35:43 -0600 (MDT) Received: from [192.168.1.113] ([70.64.1.86]) by l-daemon (Sun ONE Messaging Server 6.0 HotFix 1.01 (built Mar 15 2004)) with ESMTP id <0JMD00CKGIR9A5T0@l-daemon> for linuxppc-dev@ozlabs.org; Mon, 06 Aug 2007 16:35:33 -0600 (MDT) Date: Mon, 06 Aug 2007 16:35:25 -0600 From: Robert Hancock Subject: Re: [PATCH 2.6.22.y] ieee1394: revert "sbp2: enforce 32bit DMA mapping" In-reply-to: <1186439529.938.95.camel@localhost.localdomain> To: Benjamin Herrenschmidt Message-id: <46B7A22D.4030909@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=UTF-8; format=flowed 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> Cc: linuxppc-dev@ozlabs.org, Stefan Richter , stable@kernel.org, linux-kernel@vger.kernel.org, Olaf Hering List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Benjamin Herrenschmidt wrote: > On Mon, 2007-08-06 at 16:25 -0600, Robert Hancock wrote: >>> Anyway. For now I will simply go with what 2.6.23-rc has and what >>> 2.6.21 had: No dma_set_mask anywhere in the 1394 subsystem. We can >>> revisit this whenever an actual need arises. >> Not sure this is a very good idea. This seems rather likely to fail on >> x86_64 machines with >4GB of RAM for example.. > > Would it ? Isn't the default DMA mask for PCI devices set to 32 bits > anyway ? In which case, swiotlb will take care of the matter. > > Cheers, > Ben. Hmm, that's true, yes. Suppose it shouldn't be a problem then. 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.. -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/