Received: by 10.223.176.5 with SMTP id f5csp1088325wra; Wed, 31 Jan 2018 00:54:21 -0800 (PST) X-Google-Smtp-Source: AH8x2243UTVNNomie+TllDLEvzBv6j+uykDJNandLFjke0za/Te4sfJOzYpisdKMoktTZAh/W6Uu X-Received: by 2002:a17:902:4222:: with SMTP id g31-v6mr27701456pld.203.1517388861855; Wed, 31 Jan 2018 00:54:21 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1517388861; cv=none; d=google.com; s=arc-20160816; b=O282qVaZMQkxEN0ud1QcyV8PrUeQ+HaQbpSlLoGymmntcsG5W+2BeBrwjM+HmfPlTI kvap5TTGhLUEFbSF7MNc6is0zwCbEoB8BiT0Oz3tKoVZofKtPIC3RIol4MULVSLDHPGG Mpvf/of8Hl894ylHkNHRiUvgIVeksDvPwGWfbtSEGti+Ex9VecbkxQYuiRzMXBn0l/UX U0nnbPKIY8RpflvQFemAR+ISDxwLCuc39KULViuo4Rv3SA/wTzGoQBsEmXQpImLCadkj /kjr8NAwivAYrUiSam4wHCHe5a0tdfEyGRbFu4JoW55WVspgpKBDPM527vCjgnipHRC0 2TeA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-transfer-encoding:content-disposition:mime-version :references:message-id:subject:cc:to:from:date :arc-authentication-results; bh=mOJGTq7F+TvXY+hbMUAJ7+qFjuPwcghW09NrECR0qA0=; b=n1vwmWPSs5oLtnL+O15paDl9jHIu3ulN08amGv/yPUUgyzWGwXP8PLOGG1cx7lA3No vhwBY9+BZHE3C+eoDYP84OcMIkrNSIaA6QJMiPgBXtSwzNjg/Bx2TnKP30Ijdcf8A9E9 58OZToT7DxEk/cuL9jJaxdSWim/hybc8c3Y1khQ5YzGDfalKWBMcGxs2E4Awg4n7tZsd qn8XAt3Yn/hbvEB2TExrLkZQlGGdbtRDqyivJ1lqfb0qayeVQS83FzjxsZt0CepaXeJv ch3bwKuGQB52XD6zO6DwrhGWi+/OsV1RRpT3uAbyGya8wx+DrTt4qlafzdmSIVFcnt0q 0mqw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h66si1691120pfk.275.2018.01.31.00.54.05; Wed, 31 Jan 2018 00:54:21 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753324AbeAaIid (ORCPT + 99 others); Wed, 31 Jan 2018 03:38:33 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:57694 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751966AbeAaIic (ORCPT ); Wed, 31 Jan 2018 03:38:32 -0500 Received: from localhost (unknown [37.170.66.23]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 0DA57E34; Wed, 31 Jan 2018 08:38:30 +0000 (UTC) Date: Wed, 31 Jan 2018 09:38:27 +0100 From: Greg KH To: alexey Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] staging: android: ion: Add implementation of dma_buf_vmap and dma_buf_vunmap Message-ID: <20180131083827.GB32583@kroah.com> References: <1517344753-29021-1-git-send-email-alexey.skidanov@intel.com> <20180130221501.GA6717@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.3 (2018-01-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 31, 2018 at 01:44:47AM +0200, alexey wrote: > > > On 01/31/2018 12:15 AM, Greg KH wrote: > > On Tue, Jan 30, 2018 at 10:39:13PM +0200, Alexey Skidanov wrote: > > > dma_buf_vmap and dma_buf_vunmap allow drivers to access buffers, created by ion. > > But why would anyone ever want to do that? What is wrong with the > > existing interfaces that drivers use to access buffers created by ion? > Any driver, sharing the buffers, created by ion, through dma-buf, may get > back the > sgtable describing the buffer for device DMA? and may call dma_buf_vmap to > get back > the kernel virtual address of the buffer to get access to it. Currently, the > second > option is missing. Actually, the buffer already mapped by ion > implementation. Very odd formatting :( Anyway, as Dan said, this needs to be put in the changelog text itself. I know Intel has documentation and training for how to submit patches to the kernel properly. Please use that resource and get your patch submission reviewed by someone from the Linux kernel team at Intel before resending this. Don't force the community to help you learn this when you have people whose job it is to help out with this at your company :) thanks, greg k-h