From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Date: Thu, 31 Aug 2017 14:06:53 +0000 Subject: Re: [PATCH 04/12] x86: make dma_cache_sync a no-op Message-Id: List-Id: References: <20170827161032.22772-1-hch@lst.de> <20170827161032.22772-5-hch@lst.de> In-Reply-To: <20170827161032.22772-5-hch-jcswGhMUV9g@public.gmane.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig Cc: Chris Zankel , Michal Simek , linux-ia64-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mips-6z/3iImG2C8G8FEW9MqTrA@public.gmane.org, linux-sh-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-xtensa-PjhNF2WwrV/0Sa2dR60CXw@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, David Howells , Max Filippov , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Guan Xuetao On Sun, 27 Aug 2017, Christoph Hellwig wrote: > x86 does not implement DMA_ATTR_NON_CONSISTENT allocations, so it doesn't > make any sense to do any work in dma_cache_sync given that it must be a > no-op when dma_alloc_attrs returns coherent memory. > > Signed-off-by: Christoph Hellwig > --- > arch/x86/include/asm/dma-mapping.h | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h > index 398c79889f5c..04877267ad18 100644 > --- a/arch/x86/include/asm/dma-mapping.h > +++ b/arch/x86/include/asm/dma-mapping.h > @@ -70,7 +70,6 @@ static inline void > dma_cache_sync(struct device *dev, void *vaddr, size_t size, > enum dma_data_direction dir) > { > - flush_write_buffers(); > } > > static inline unsigned long dma_alloc_coherent_mask(struct device *dev, > -- > 2.11.0 > >