Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966613Ab2JZVvK (ORCPT ); Fri, 26 Oct 2012 17:51:10 -0400 Received: from g4t0014.houston.hp.com ([15.201.24.17]:40304 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964839Ab2JZVvI (ORCPT ); Fri, 26 Oct 2012 17:51:08 -0400 Message-ID: <1351288264.6885.11.camel@lorien2> Subject: Re: [PATCH RFT RESEND linux-next] mips: dma-mapping: support debug_dma_mapping_error From: Shuah Khan Reply-To: shuah.khan@hp.com To: David Daney Cc: ralf@linux-mips.org, kyungmin.park@samsung.com, arnd@arndb.de, andrzej.p@samsung.com, m.szyprowski@samsung.com, linux-mips@linux-mips.org, LKML , shuahkhan@gmail.com Date: Fri, 26 Oct 2012 15:51:04 -0600 In-Reply-To: <508AED66.3040808@gmail.com> References: <1351208193.6851.17.camel@lorien2> <1351267298.4013.12.camel@lorien2> <508ABE1D.5010106@gmail.com> <1351271198.4013.35.camel@lorien2> <508AED66.3040808@gmail.com> Organization: ISS-Linux Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2735 Lines: 73 On Fri, 2012-10-26 at 13:07 -0700, David Daney wrote: > On 10/26/2012 10:06 AM, Shuah Khan wrote: > > On Fri, 2012-10-26 at 09:45 -0700, David Daney wrote: > >> On 10/26/2012 09:01 AM, Shuah Khan wrote: > >>> Add support for debug_dma_mapping_error() call to avoid warning from > >>> debug_dma_unmap() interface when it checks for mapping error checked > >>> status. Without this patch, device driver failed to check map error > >>> warning is generated. > >>> > >>> Signed-off-by: Shuah Khan > >>> --- > >>> arch/mips/include/asm/dma-mapping.h | 2 ++ > >>> 1 file changed, 2 insertions(+) > >>> > >>> diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h > >>> index be39a12..006b43e 100644 > >>> --- a/arch/mips/include/asm/dma-mapping.h > >>> +++ b/arch/mips/include/asm/dma-mapping.h > >>> @@ -40,6 +40,8 @@ static inline int dma_supported(struct device *dev, u64 mask) > >>> static inline int dma_mapping_error(struct device *dev, u64 mask) > >>> { > >>> struct dma_map_ops *ops = get_dma_ops(dev); > >>> + > >>> + debug_dma_mapping_error(dev, mask); > >>> return ops->mapping_error(dev, mask); > >>> } > >>> > >>> > >> > >> Although this is a start, I don't think it is sufficient. > >> > >> As far as I can tell, there are many missing calls to debug_dma_*() in > >> the various MIPS commone and sub-architecture DMA code. > >> > >> Really you (or someone) needs to look at *all* the functions in > >> arch/mips/asm/dma-mapping.h, and arch/mips/mm/dma-default.c and find > >> places missing a debug_dma_*(). > > > > Is it correct to assume that this patch is not needed on MIPS until > > debug_dma interfaces get added to MIPS common and sub-architecture DMA > > code. > > No, you have a false predicate here. > > debug_dma_* *is* already mostly added. The problem is that it is > incomplete. That is the nature of the problem. Your patch makes it > slightly better, but doesn't fully fix the problems. Got it. Thanks. I would volunteer to look at fixing all the problems, but unfortunately I don't have a MIPS box handy for a thorough testing that would be necessary for such a change. -- Shuah > > > > > > When I didn't see dma_map_page() in arch/mips/include/asm/dma-mapping.h > > defined, and just an extern, I incorrectly assumed, it is getting picked > > up from , hence the need for this > > patch in the first place. > > > > -- Shuah > > > > > > > -- 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/