Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763940AbZFQCh7 (ORCPT ); Tue, 16 Jun 2009 22:37:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753997AbZFQChw (ORCPT ); Tue, 16 Jun 2009 22:37:52 -0400 Received: from exprod7og120.obsmtp.com ([64.18.2.18]:53631 "HELO exprod7og120.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753979AbZFQChv convert rfc822-to-8bit (ORCPT ); Tue, 16 Jun 2009 22:37:51 -0400 MIME-Version: 1.0 In-Reply-To: <20090617111443B.fujita.tomonori@lab.ntt.co.jp> References: <20090617111443B.fujita.tomonori@lab.ntt.co.jp> Date: Wed, 17 Jun 2009 12:07:53 +0930 Message-ID: <2e115de50906161937j1fc9e28dxd9622b0092ddc997@mail.gmail.com> Subject: Re: [PATCH] parport_pc: set properly the dma_mask for parport_pc device From: Malcom Blaney To: FUJITA Tomonori Cc: alan@linux.intel.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.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: 2190 Lines: 53 I used this with a patch I worked on a few years ago to fix ECP reads from the parport. If anyone is interested it can be found at: http://lists.infradead.org/pipermail/linux-parport/2007-October/000614.html 2009/6/17 FUJITA Tomonori : > parport_pc_probe_port() creates the own 'parport_pc' device if the > device argument is NULL. Then parport_pc_probe_port() doesn't > initialize the dma_mask and coherent_dma_mask of the device and calls > dma_alloc_coherent with it. dma_alloc_coherent fails because > dma_alloc_coherent() doesn't accept the uninitialized dma_mask: > > http://lkml.org/lkml/2009/6/16/150 > > Long ago, 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. When we merged them, we chose to > prohibit a device having dma_mask that is not initialized. I think > that it's good to require drivers to set up dma_mask (and > coherent_dma_mask) properly if the drivers want DMA. > > Signed-off-by: FUJITA Tomonori > Reported-by: Malcom Blaney > Tested-by: Malcom Blaney > Cc: stable@kernel.org > --- > ?drivers/parport/parport_pc.c | ? ?3 +++ > ?1 files changed, 3 insertions(+), 0 deletions(-) > > 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); > -- > 1.6.0.6 > > -- 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/