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[213.95.11.211]) by mx.google.com with ESMTPS id q9si259190wmd.184.2019.07.08.11.43.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Jul 2019 11:43:52 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of hch@lst.de designates 213.95.11.211 as permitted sender) client-ip=213.95.11.211; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of hch@lst.de designates 213.95.11.211 as permitted sender) smtp.mailfrom=hch@lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 8C7F2227A81; Mon, 8 Jul 2019 20:43:51 +0200 (CEST) Date: Mon, 8 Jul 2019 20:43:51 +0200 From: Christoph Hellwig To: Arend Van Spriel Cc: Christoph Hellwig , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Ian Abbott , H Hartley Sweeten , devel@driverdev.osuosl.org, linux-s390@vger.kernel.org, Intel Linux Wireless , linux-rdma@vger.kernel.org, netdev@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, "moderated list:ARM PORT" , linux-media@vger.kernel.org Subject: Re: use exact allocation for dma coherent memory Message-ID: <20190708184351.GA12877@lst.de> References: <20190614134726.3827-1-hch@lst.de> <20190701084833.GA22927@lst.de> <74eb9d99-6aa6-d1ad-e66d-6cc9c496b2f3@broadcom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <74eb9d99-6aa6-d1ad-e66d-6cc9c496b2f3@broadcom.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Jul 02, 2019 at 11:48:44AM +0200, Arend Van Spriel wrote: > You made me look ;-) Actually not touching my drivers so I'm off the hook. > However, I was wondering if drivers could know so I decided to look into > the DMA-API.txt documentation which currently states: > > """ > The flag parameter (dma_alloc_coherent() only) allows the caller to > specify the ``GFP_`` flags (see kmalloc()) for the allocation (the > implementation may choose to ignore flags that affect the location of > the returned memory, like GFP_DMA). > """ > > I do expect you are going to change that description as well now that you > are going to issue a warning on __GFP_COMP. Maybe include that in patch > 15/16 where you introduce that warning. Yes, that description needs an updated, even without this series. I'll make sure it is more clear.