From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 142E8C04AAC for ; Mon, 20 May 2019 17:35:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF034214AE for ; Mon, 20 May 2019 17:35:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NHqq3GHE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392997AbfETRft (ORCPT ); Mon, 20 May 2019 13:35:49 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50662 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387560AbfETRfs (ORCPT ); Mon, 20 May 2019 13:35:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=CsywoW2o9YLJ9jNz4GPRvKpa5ukQ3xRtuV6BLonYynA=; b=NHqq3GHEI2/OOEZKX18l+tkn1 e3rnjH1uM68rWoVn71z0EZyHPciGMMKLu78t+vx3/z6SDv1J/T6zODYL3dYkURh4g52GtL2p775zY BTn+1XF/8uzEGJiYFUjyz/pKuwyLwdrKAtAypr8/YcAUYTObVqsH6Osdc1QNOQ5QNtjK8YVaGIBD2 rduLKlJ/iJBrd1nhLVr3WkJLmvU6J3U81uE96zMQSdAHi6rauC1lWWlL01OLVeWqv8h+G0jnqL2Ck c81G+Z/8pSX3tslABXBPnEF9lL7iIacISnPg/c7uKLwFLNXhUdMBJfYCxv7W7pFsrdGKl/MXqIOzX NDMX0E5Cw==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1hSmCM-0007tV-0l; Mon, 20 May 2019 17:35:42 +0000 Date: Mon, 20 May 2019 10:35:41 -0700 From: Christoph Hellwig To: Alex Elder Cc: Arnd Bergmann , David Miller , Bjorn Andersson , Ilias Apalodimas , syadagir@codeaurora.org, mjavid@codeaurora.org, evgreen@chromium.org, Ben Chan , Eric Caruso , abhishek.esse@gmail.com, Linux Kernel Mailing List , Christoph Hellwig Subject: Re: [PATCH 12/18] soc: qcom: ipa: immediate commands Message-ID: <20190520173541.GA30280@infradead.org> References: <20190512012508.10608-1-elder@linaro.org> <20190512012508.10608-13-elder@linaro.org> <5d948d74-f739-0cfa-8fae-b15c20fbe7ec@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 20, 2019 at 09:55:42AM -0500, Alex Elder wrote: > On 5/20/19 9:50 AM, Arnd Bergmann wrote: > > Ok, that sounds reasonable, yes. I'm not sure if > > dma_alloc_coherent() guarantees zero-initialization > > though, so if that is required, you may have to > > add a memset(). > I had dma_zalloc_coherent() originally but I think > Christoph Hellwig posted something recently that > removed that function, because dma_alloc_coherent() > always zeroes the underlying memory. > > +Christoph, who might be able to explain or confirm dma_alloc_coherent always zeroes the returned memory, which is why dma_zalloc_coherent has been removed.