Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752501Ab2H0LOj (ORCPT ); Mon, 27 Aug 2012 07:14:39 -0400 Received: from cassarossa.samfundet.no ([129.241.93.19]:43318 "EHLO cassarossa.samfundet.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751730Ab2H0LOi (ORCPT ); Mon, 27 Aug 2012 07:14:38 -0400 Date: Mon, 27 Aug 2012 13:14:31 +0200 From: Hans-Christian Egtvedt To: Hein Tibosch Cc: viresh kumar , spear-devel , Linux Kernel Mailing List , "ludovic.desroches" , Havard Skinnemoen , Nicolas Ferre , Andrew Morton , Arnd Bergmann Subject: Re: [PATCH 1/2] dw_dmac: make driver endianness configurable Message-ID: <20120827111431.GA27868@samfundet.no> References: <503A8CAE.6050606@yahoo.es> <20120827070323.GC28721@samfundet.no> <503B342C.9060300@yahoo.es> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <503B342C.9060300@yahoo.es> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1868 Lines: 56 Around Mon 27 Aug 2012 16:47:40 +0800 or thereabout, Hein Tibosch wrote: > On 8/27/2012 3:03 PM, Hans-Christian Egtvedt wrote: >> I think the English in kconfig could use some brushing up. >> >>> +config DW_DMAC_BE >> >> >> This name isn't that long, so we could skip the abbreviation of big endian; >> DW_DMAC_BIG_ENDIAN_IO or something similar? >> >>> + bool "Synopsys DesignWare AHB DMA needs big endian access" >>> >> bool "Use big endian I/O register access" > > Brushing up the config items: > > +config DW_DMAC_BIG_ENDIAN_IO > + bool "Use big endian I/O register access" > + default y if AVR32 > + depends on DW_DMAC > + help > + Say yes here to use big endian I/O access when reading and writing > + to the DMA controller registers. This is needed on some platforms, > + like the Atmel AVR32 architecture. > + > + If unsure, use the default setting. This sounds good in my ears, but I don't speak English natively. > And as I'd like to define the maximum memory transfer width in the same > Kconfig: > > +config DW_DMAC_MEM_64_BIT > + bool "Allow 64-bit memory transfers" > + default y if !AVR32 > + depends on DW_DMAC > + help > + Say yes if the DMA controller may do 64-bit memory transfers > + For AVR32, say no because only up to 32-bit transfers are > + defined Is this sane to add? Could some non-AVR32 platforms use 64-bit and 32-bit depending on runtime configuration? E.g. if you build a kernel with support for multiple boards/processors, and there is a mix of 32-bit and 64-bit wide DMA support. I think it is better to select 32/64-bit at runtime. -- mvh Hans-Christian Egtvedt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/