From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH 7/8] common: dma-mapping: change alloc/free_coherent method to more generic alloc/free_attrs Date: Mon, 20 Jun 2011 16:06:10 +0100 Message-ID: <20110620150610.GG26089@n2100.arm.linux.org.uk> References: <1308556213-24970-1-git-send-email-m.szyprowski@samsung.com> <1308556213-24970-8-git-send-email-m.szyprowski@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: KyongHo Cho Cc: linux-arch@vger.kernel.org, Arnd Bergmann , Joerg Roedel , linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, Kyungmin Park , linux-arm-kernel@lists.infradead.org, Marek Szyprowski List-Id: linux-arch.vger.kernel.org On Mon, Jun 20, 2011 at 11:45:41PM +0900, KyongHo Cho wrote: > I still don't agree with your idea that change alloc_coherent() with alloc(). > As I said before, we actually do not need dma_alloc_writecombine() anymore > because it is not different from dma_alloc_coherent() in ARM. Wrong - there is a difference. For pre-ARMv6 CPUs, it returns memory with different attributes from DMA coherent memory. And we're not going to sweep away pre-ARMv6 CPUs any time soon. So you can't ignore dma_alloc_writecombine() which must remain to sanely support framebuffers. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:37797 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751386Ab1FTPHB (ORCPT ); Mon, 20 Jun 2011 11:07:01 -0400 Date: Mon, 20 Jun 2011 16:06:10 +0100 From: Russell King - ARM Linux Subject: Re: [PATCH 7/8] common: dma-mapping: change alloc/free_coherent method to more generic alloc/free_attrs Message-ID: <20110620150610.GG26089@n2100.arm.linux.org.uk> References: <1308556213-24970-1-git-send-email-m.szyprowski@samsung.com> <1308556213-24970-8-git-send-email-m.szyprowski@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: To: KyongHo Cho Cc: Marek Szyprowski , linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, Kyungmin Park , Arnd Bergmann , Joerg Roedel Message-ID: <20110620150610.3hT7JhHnhcABZQ9BUAhOfUMyX3VEAiy4NZIyID1090U@z> On Mon, Jun 20, 2011 at 11:45:41PM +0900, KyongHo Cho wrote: > I still don't agree with your idea that change alloc_coherent() with alloc(). > As I said before, we actually do not need dma_alloc_writecombine() anymore > because it is not different from dma_alloc_coherent() in ARM. Wrong - there is a difference. For pre-ARMv6 CPUs, it returns memory with different attributes from DMA coherent memory. And we're not going to sweep away pre-ARMv6 CPUs any time soon. So you can't ignore dma_alloc_writecombine() which must remain to sanely support framebuffers.