Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932164AbdL2JSu (ORCPT ); Fri, 29 Dec 2017 04:18:50 -0500 Received: from fllnx209.ext.ti.com ([198.47.19.16]:31569 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754830AbdL2JSq (ORCPT ); Fri, 29 Dec 2017 04:18:46 -0500 Subject: Re: [PATCH 0/3] mtd: spi-nor: fix DMA-unsafe buffer issue between MTD and SPI To: Trent Piepho , "linux-mtd@lists.infradead.org" , "linux@armlinux.org.uk" , "broonie@kernel.org" , "cyrille.pitchen@wedev4u.fr" , "dwmw2@infradead.org" , "computersforpeace@gmail.com" , "boris.brezillon@free-electrons.com" , "richard@nod.at" , "marek.vasut@gmail.com" CC: "linux-spi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "nicolas.ferre@microchip.com" , "robh@kernel.org" , "radu.pirea@microchip.com" , "devicetree@vger.kernel.org" References: <1514313927.26695.19.camel@impinj.com> From: Vignesh R Message-ID: <46499c32-f513-1781-bb42-f56b1f534941@ti.com> Date: Fri, 29 Dec 2017 14:46:31 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <1514313927.26695.19.camel@impinj.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 763 Lines: 24 On Wednesday 27 December 2017 12:15 AM, Trent Piepho wrote: > On Sun, 2017-12-24 at 05:36 +0100, Cyrille Pitchen wrote: >> this series tries to solve a long time issue of compatibility between the >> MTD and SPI sub-systems about whether we should use DMA-safe memory. > > Can this should replace SoC specific fixes like: > > c687c46e9e45 > spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble > Yes, I plan to revert this patch once m25p80 starts using bounce buffers. I am interested in knowing which other SPI clients end up passing non DMA'able buffers. AFAIK, its UBIFS and JFFS2. Most other SPI devices on TI boards that I have dealt with like Touch, Sensors (IIO), GPIO expanders etc all provide DMA'able buffers. -- Regards Vignesh