From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753542AbcHQFNa (ORCPT ); Wed, 17 Aug 2016 01:13:30 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:58380 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750974AbcHQFN1 (ORCPT ); Wed, 17 Aug 2016 01:13:27 -0400 Subject: Re: [PATCH v5] spi: spi-ti-qspi: Add DMA support for QSPI mmap read To: Mark Brown References: <20160809110311.13521-1-vigneshr@ti.com> <20160809113329.GA9347@sirena.org.uk> <13e676c2-7e2f-d1c5-5312-bc2e11a6b6a1@ti.com> <20160816184253.GC9347@sirena.org.uk> CC: "linux-spi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-omap@vger.kernel.org" From: Vignesh R Message-ID: <7f441117-8fd9-6681-70c8-85fb6de40631@ti.com> Date: Wed, 17 Aug 2016 10:43:12 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20160816184253.GC9347@sirena.org.uk> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 17 August 2016 12:12 AM, Mark Brown wrote: > On Tue, Aug 09, 2016 at 06:20:01PM +0530, Vignesh R wrote: >> >> > >> According to this thread[1], converting virtual address >> pointer into scatterlist which is then DMA mapped is unsafe on systems >> with certain cache architecture. Hence, I added code to handle kmap >> buffers inside the driver rather than updating generic spi-core code. > > That's saying that things that aren't covered aren't DMAable safely at > all which is a more general issue... > >> If its okay to update the spi_map_buf() to handle kmap buffers as above >> then I can submit the patch accordingly. > > Yes, the whole point is that this is all in generic code so drivers > don't need to worry about it. Ok, I will send another version updating spi_map_buf() to handle kmap buffers. Thanks! -- Regards Vignesh