Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758841AbZFQBKm (ORCPT ); Tue, 16 Jun 2009 21:10:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762976AbZFQBKL (ORCPT ); Tue, 16 Jun 2009 21:10:11 -0400 Received: from exprod7og105.obsmtp.com ([64.18.2.163]:54425 "HELO exprod7og105.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1761803AbZFQBKJ convert rfc822-to-8bit (ORCPT ); Tue, 16 Jun 2009 21:10:09 -0400 MIME-Version: 1.0 In-Reply-To: <20090616175549Y.fujita.tomonori@lab.ntt.co.jp> References: <2e115de50906160024r7c3140d6sc8744e4362d36ef8@mail.gmail.com> <20090616171029H.fujita.tomonori@lab.ntt.co.jp> <2e115de50906160123n20791768sd154621b0d95ca50@mail.gmail.com> <20090616175549Y.fujita.tomonori@lab.ntt.co.jp> Date: Wed, 17 Jun 2009 10:40:10 +0930 Message-ID: <2e115de50906161810j48db4b42if2dae7c48df4116b@mail.gmail.com> Subject: Re: is_device_dma_capable From: Malcom Blaney To: FUJITA Tomonori Cc: linux-kernel@vger.kernel.org, linux-parport@lists.infradead.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2037 Lines: 54 Thanks Fujita, your patch worked a treat! 2009/6/16 FUJITA Tomonori : > On Tue, 16 Jun 2009 17:53:03 +0930 > Malcom Blaney wrote: > >> Hi Fujita, >> >> 2009/6/16 FUJITA Tomonori : >> > You use X86_32, right? >> >> I have CONFIG_X86_32=y in my config file. >> >> > >> > In 2.6.25, X86_32 and X86_64 had the own dma_alloc_coherent >> > implementations; X86_32 accepted a device having dma_mask that is not >> > initialized however X86_64 didn't, I think. >> > >> > When we merged them, we chose to prohibit a device having dma_mask >> > that is not initialized. I'm not sure the DMA docs say this but IMO >> > it's good to require drivers to set up dma_mask (and >> > coherent_dma_mask) properly if the drivers want DMA. >> > >> >> If you could point me in the direction of how to set these values >> correctly, I would appreciate it. > > You hit the problem that a device that parport_pc_probe_port creates > but doesn't set up the dma_mask properly, right (I'm not familiar with > the driver at all so I might misunderstand something)? > > If so, I guess that the following patch works (only compile tested). > > > diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c > index 151bf5b..1af57b7 100644 > --- a/drivers/parport/parport_pc.c > +++ b/drivers/parport/parport_pc.c > @@ -2271,6 +2271,9 @@ struct parport *parport_pc_probe_port(unsigned long int base, > ? ? ? ? ? ? ? ?if (IS_ERR(pdev)) > ? ? ? ? ? ? ? ? ? ? ? ?return NULL; > ? ? ? ? ? ? ? ?dev = &pdev->dev; > + > + ? ? ? ? ? ? ? dev->coherent_dma_mask = DMA_BIT_MASK(24); > + ? ? ? ? ? ? ? dev->dma_mask = &dev->coherent_dma_mask; > ? ? ? ?} > > ? ? ? ?ops = kmalloc(sizeof(struct parport_operations), GFP_KERNEL); > -- 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/