From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751499AbdIRFWw (ORCPT ); Mon, 18 Sep 2017 01:22:52 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:52673 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750816AbdIRFWu (ORCPT ); Mon, 18 Sep 2017 01:22:50 -0400 Date: Sun, 17 Sep 2017 22:22:45 -0700 From: Christoph Hellwig To: Huacai Chen Cc: Marek Szyprowski , Robin Murphy , Andrew Morton , Fuxin Zhang , linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH V5 1/3] dma-mapping: Introduce device_is_coherent() as a helper Message-ID: <20170918052245.GC29118@infradead.org> References: <1505708500-3743-1-git-send-email-chenhc@lemote.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1505708500-3743-1-git-send-email-chenhc@lemote.com> User-Agent: Mutt/1.8.3 (2017-05-23) 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 18, 2017 at 12:21:40PM +0800, Huacai Chen wrote: > We will use device_is_coherent() as a helper function, in order to set > an appropriate dma alignment in dmapool and block queue (other patches > in this series). > > There is a MIPS-specific plat_device_is_coherent(), but we need a more > generic solution, so add and use a new function pointer in dma_map_ops. This is still missing any explanation on what this API could do with the information, and both of the callers in the series don't actually need it.