Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764968AbXHDROT (ORCPT ); Sat, 4 Aug 2007 13:14:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760709AbXHDROM (ORCPT ); Sat, 4 Aug 2007 13:14:12 -0400 Received: from shawidc-mo1.cg.shawcable.net ([24.71.223.10]:31216 "EHLO pd3mo1so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760644AbXHDROK (ORCPT ); Sat, 4 Aug 2007 13:14:10 -0400 Date: Sat, 04 Aug 2007 11:14:04 -0600 From: Robert Hancock Subject: Re: [PATCH 2.6.22.y] ieee1394: revert "sbp2: enforce 32bit DMA mapping" In-reply-to: To: Stefan Richter Cc: stable@kernel.org, linux-kernel@vger.kernel.org Message-id: <46B4B3DC.7020609@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit References: User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2118 Lines: 58 Stefan Richter wrote: > Date: Wed, 1 Aug 2007 20:30:36 +0200 (CEST) > From: Stefan Richter > Subject: ieee1394: revert "sbp2: enforce 32bit DMA mapping" > > Revert commit 0555659d63c285ceb7ead3115532e1b71b0f27a7 from 2.6.22-rc1. > The dma_set_mask call somehow failed on a PowerMac G5, PPC64: > http://lkml.org/lkml/2007/8/1/344 > > Should there ever occur a DMA mapping beyond the physical DMA range, a > proper SBP-2 firmware will report transport errors. So let's leave it > at that. Isn't this a rather poor workaround? All this means is that if we fail to set a 32-bit DMA mask, we're likely to blow up at runtime instead of at initialization time, when we get a DMA mapping over 4GB. If setting 32-bit DMA mask fails on ppc64, that sounds like a problem with the DMA implementation on that architecture. There are enough cards out there that only support 32-bit DMA that this really needs to work.. > > Signed-off-by: Stefan Richter > Tested-by: Olaf Hering > --- > Same as commit a9c2f18800753c82c45fc13b27bdc148849bdbb2. > > drivers/ieee1394/sbp2.c | 5 ----- > 1 file changed, 5 deletions(-) > > Index: linux-2.6.22/drivers/ieee1394/sbp2.c > =================================================================== > --- linux-2.6.22.orig/drivers/ieee1394/sbp2.c > +++ linux-2.6.22/drivers/ieee1394/sbp2.c > @@ -774,11 +774,6 @@ static struct sbp2_lu *sbp2_alloc_device > SBP2_ERR("failed to register lower 4GB address range"); > goto failed_alloc; > } > -#else > - if (dma_set_mask(hi->host->device.parent, DMA_32BIT_MASK)) { > - SBP2_ERR("failed to set 4GB DMA mask"); > - goto failed_alloc; > - } > #endif > } > > -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@nospamshaw.ca Home Page: http://www.roberthancock.com/ - 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/