Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754759Ab0KLDQK (ORCPT ); Thu, 11 Nov 2010 22:16:10 -0500 Received: from am1ehsobe006.messaging.microsoft.com ([213.199.154.209]:4175 "EHLO AM1EHSOBE006.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752492Ab0KLDQF convert rfc822-to-8bit (ORCPT ); Thu, 11 Nov 2010 22:16:05 -0500 X-SpamScore: -20 X-BigFish: VS-20(zz1432N98dN9371Pzz1202hzz8275bhz2dh2a8h668h61h) X-Spam-TCS-SCL: 0:0 X-Forefront-Antispam-Report: KIP:(null);UIP:(null);IPVD:NLI;H:de01egw02.freescale.net;RD:de01egw02.freescale.net;EFVD:NLI X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-Class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 8BIT Subject: RE: [PATCH v2] fsldma: add support to 36-bit physical address Date: Fri, 12 Nov 2010 11:16:46 +0800 Message-ID: In-Reply-To: <54AAF9B7-9533-45B8-9C49-A964203AF707@kernel.crashing.org> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [PATCH v2] fsldma: add support to 36-bit physical address Thread-Index: AcuBl6G+cKeNGvhMSLWOgx0eJyTNgAAf1USg References: <1289477789-10651-1-git-send-email-leoli@freescale.com> <54AAF9B7-9533-45B8-9C49-A964203AF707@kernel.crashing.org> From: Li Yang-R58472 To: Kumar Gala CC: , , X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1945 Lines: 50 >Subject: Re: [PATCH v2] fsldma: add support to 36-bit physical address > > >On Nov 11, 2010, at 6:16 AM, Li Yang wrote: > >> Expand the dma_mask of fsldma device to 36-bit, indicating that the >> DMA engine can deal with 36-bit physical address and does not need the >> SWIOTLB to create bounce buffer for it when doing dma_map_*(). >> >> Signed-off-by: Li Yang >> --- >> Add more detailed commit message >> >> drivers/dma/fsldma.c | 4 +++- >> 1 files changed, 3 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index >> cea08be..8c79b37 100644 >> --- a/drivers/dma/fsldma.c >> +++ b/drivers/dma/fsldma.c >> @@ -1,7 +1,7 @@ >> /* >> * Freescale MPC85xx, MPC83xx DMA Engine support >> * >> - * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved. >> + * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights >reserved. >> * >> * Author: >> * Zhang Wei , Jul 2007 >> @@ -1338,6 +1338,8 @@ static int __devinit fsldma_of_probe(struct >platform_device *op, >> fdev->common.device_control = fsl_dma_device_control; >> fdev->common.dev = &op->dev; >> >> + dma_set_mask(&(op->dev), DMA_BIT_MASK(36)); >> + > >Is there any reason we shouldn't set DMA_BIT_MASK(64) since the DMA block >programming model allows the address to be 64-bits? The current code is only verified on chips with 36-bit physical address. I'm not sure if the driver can work without any change on the 64-bit chip, although the register model suggests it can work well with 64-bit. If you can confirm that it's compatible with the block on 64-bit chip, then we can change it to 64 bit dma mask. - Leo -- 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/