From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752745AbbLJJCQ (ORCPT ); Thu, 10 Dec 2015 04:02:16 -0500 Received: from mail-ob0-f177.google.com ([209.85.214.177]:34466 "EHLO mail-ob0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118AbbLJJCN (ORCPT ); Thu, 10 Dec 2015 04:02:13 -0500 MIME-Version: 1.0 In-Reply-To: <20151210022146.GH144338@google.com> References: <3152458.D3kElfhRW2@wuerfel> <20151210022146.GH144338@google.com> Date: Thu, 10 Dec 2015 10:02:06 +0100 X-Google-Sender-Auth: -qEqL6kfzYlhFK3aXvNgdoQ_C4k Message-ID: Subject: Re: [PATCH] mtd: sh_flctl: pass FIFO as physical address From: Geert Uytterhoeven To: Brian Norris Cc: Arnd Bergmann , MTD Maling List , Boris BREZILLON , Kuninori Morimoto , Linux-sh list , Magnus Damm , "linux-kernel@vger.kernel.org" , Simon Horman , Frans Klaver , David Woodhouse , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Brian, On Thu, Dec 10, 2015 at 3:21 AM, Brian Norris wrote: > On Tue, Dec 08, 2015 at 05:30:02PM +0100, Geert Uytterhoeven wrote: >> On Tue, Dec 8, 2015 at 4:38 PM, Arnd Bergmann wrote: >> > By convention, the FIFO address we pass using dmaengine_slave_config >> > is a physical address in the form that is understood by the DMA >> > engine, as a dma_addr_t, phys_addr_t or resource_size_t. >> > >> > The sh_flctl driver however passes a virtual __iomem address that >> > gets cast to dma_addr_t in the slave driver. This happens to work >> > on shmobile because that platform sets up an identity mapping for >> > its MMIO regions, but such code is not portable to other platforms, >> > and prevents us from ever changing the platform mapping or reusing >> > the driver on other architectures like ARM64 that might not have the >> > mapping. >> >> Note that since the removal of (ARM) sh7367/sh7377/sh7372 support, this >> driver is used on SH only. > > It's still available as COMPILE_TEST, so it's still worth fixing. > > But really, does anyone use this driver any more? It's used on the sh7723-based AP-325RXA board. No idea if anyone is really using it. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds