Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753084AbbHTWCr (ORCPT ); Thu, 20 Aug 2015 18:02:47 -0400 Received: from lists.s-osg.org ([54.187.51.154]:58922 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752757AbbHTWCq (ORCPT ); Thu, 20 Aug 2015 18:02:46 -0400 Subject: Re: [PATCH 13/18] iio: adc: mcp320x: Set struct spi_driver .of_match_table To: Michael Welling References: <1440054451-1223-1-git-send-email-javier@osg.samsung.com> <1440054451-1223-14-git-send-email-javier@osg.samsung.com> <20150820200912.GA2866@deathstar> From: Javier Martinez Canillas X-Enigmail-Draft-Status: N1110 Cc: linux-kernel@vger.kernel.org, Andrea Galbusera , linux-iio@vger.kernel.org, Peter Meerwald , Lars-Peter Clausen , Manfred Schlaegl , =?UTF-8?Q?S=c3=b8ren_Andersen?= , Jonathan Cameron , Hartmut Knaack Message-ID: <55D64E80.4050502@osg.samsung.com> Date: Fri, 21 Aug 2015 00:02:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.0.1 MIME-Version: 1.0 In-Reply-To: <20150820200912.GA2866@deathstar> 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 Content-Length: 1604 Lines: 47 Hello Michael, On 08/20/2015 10:09 PM, Michael Welling wrote: > On Thu, Aug 20, 2015 at 09:07:26AM +0200, Javier Martinez Canillas wrote: >> The driver has an OF id table but the .of_match_table is not set so >> the SPI core can't do an OF style match and the table was unused. >> > > Is an OF style match necessary? > Did you read the cover letter [0] on which I explain why is needed to avoid breaking module autoloading in the future? Once the SPI core is changed by RFC patch 18/18? (you were cc'ed in the cover letter BTW). > I have been using devicetree and it matches based on the .id_table. > Yes it fallbacks to the .id_table or the driver name but the correct thing to do for devices registered by OF, is to match using the compatible string. > Couldn't we just remove the mcp320x_dt_ids table instead? > No, that is the wrong thing to do IMHO since the compatible string contains both vendor and device name whle the .id_table only contains a device name. So it makes sense to match using the compatible string and also report the OF modalias information to user-space. Otherwise what's the point of the vendor in the compatible string for SPI devices? You can just use "bar" instead of "foo,bar" as a string. [0]: https://lkml.org/lkml/2015/8/20/109 Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America -- 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/