Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755111AbbEUIjj (ORCPT ); Thu, 21 May 2015 04:39:39 -0400 Received: from mail-oi0-f51.google.com ([209.85.218.51]:35764 "EHLO mail-oi0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751140AbbEUIjf convert rfc822-to-8bit (ORCPT ); Thu, 21 May 2015 04:39:35 -0400 MIME-Version: 1.0 In-Reply-To: References: <20150515195541.GL11598@ld-irv-0074> <20150518104501.GD3551@leverpostej> <20150518183442.GR11598@ld-irv-0074> <20150519013415.GV11598@ld-irv-0074> <20150520213546.GN11598@ld-irv-0074> <20150521072515.GC11112@norris-Latitude-E6410> <20150521081526.GG11112@norris-Latitude-E6410> Date: Thu, 21 May 2015 10:39:34 +0200 X-Google-Sender-Auth: EgUXpefIercQUZzMcu_h4hsxmcw Message-ID: Subject: Re: [PATCH] Documentation: dt: mtd: replace "nor-jedec" binding with "jedec,spi-nor" From: Geert Uytterhoeven To: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Brian Norris , "linux-mtd@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Stephen Warren , Marek Vasut , linux-spi Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4293 Lines: 102 Hi Rafal, Brian, On Thu, May 21, 2015 at 10:25 AM, Rafał Miłecki wrote: > On 21 May 2015 at 10:15, Brian Norris wrote: >> On Thu, May 21, 2015 at 10:01:05AM +0200, Rafał Miłecki wrote: >>> On 21 May 2015 at 09:25, Brian Norris wrote: >>> >> > For platform devices, you might as well just use the name of the driver, >>> >> > which is 'm25p80'. Isn't that how most platform devices are matched with >>> >> > drivers? >>> >> >>> >> Yes and I think it's ugly because it keeps causing the warning about >>> >> read flash model not matching specified one (m25p80). >>> > >>> > Sure, I agree. >>> > >>> >> Are you >>> >> seriously not going to allow platform stuff *clearly* request flash >>> >> model detection (JEDEC RDID OP)? Just because they don't use DT? >>> > >>> > No, this isn't about "allowing" anything. It's just that my primary >>> > concern was to get the DT binding straightened out properly. Linus' >>> > current tree now has the proper binding, but the m25p80.c code doesn't >>> > quite bind properly. It will work if "jedec,spi-nor" is the first >>> > entry in the compatible property (and so it becomes the 'modalias', but >>> > not second, third, etc. So my patch fixes that properly. >>> > >>> > Now, the secondary concern is that you want platform devices to specify >>> > something generic, and that doesn't yield a "found X, expected Y" >>> > message. I'm perfectly fine with fixing that too, if you have a patch >>> > for it. What do you propose? >>> >>> Maybe I wasn't clear enough. I was going to start using struct >>> flash_platform_data with >>> .type = "spi-nor", >>> but your proposed patch removes support for such name. >> >> Ah, OK. So that's the part I was overlooking. >> >>> While I like matching DT *clearly* against the whole "jedec,spi-nor" >>> string (really, I'm all for it), I'm confused what I should use for >>> platform stuff now. I don't have any proposal as my initial plan was >>> exactly to use this "spi-nor". >>> I guess I don't want to re-add support for "spi-nor" (as you just >>> proposed to remove it), >> >> I wasn't really trying to remove "spi-nor", that was mostly a side >> effect. > > OK, I think we understand each other now :) > >>> so I think I have to bounce the question: what >>> alternative do you propose? >> >> I think your comments suggest that I shouldn't be removing "spi-nor" >> from m25p_ids[] nor from this block: >> >> if (data && data->type) >> flash_name = data->type; >> else if (!strcmp(spi->modalias, "spi-nor")) >> flash_name = NULL; /* auto-detect */ >> else >> flash_name = spi->modalias; >> >> So it stays in both m25p_ids[] and .of_match_table. >> >> I suppose that can work. It then allows people to do weird stuff like: >> >> compatible = "idontknowwhatimdoing,spi-nor"; >> >> in their device tree. But other than that, there's not much downside I don't >> think. > > It sounds like a reasonable solution. I guess there isn't a perfect > one. Even if we decide to go for sth like "jedec-spi-nor", there > always will be a chance of someone using > compatible = "idontknowwhatimdoing,jedec-spi-nor"; > So if you rework your patch to leave "spi-nor" support in m25p_ids and > conditions block, it should be OK. Typically platform devices just use the driver's name. Hence IMHO there's no need to add a shiny new spi-nor device name. So what's wrong with using "m25p80", and treating that as auto-detect iff !spi->dev.of_node? Non-autodetect platform_devices use flash_platform_data.type anyway, and thus fall under the first "if" clause above, don't they? 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 -- 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/