Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753612AbbHWWKo (ORCPT ); Sun, 23 Aug 2015 18:10:44 -0400 Received: from mail-yk0-f179.google.com ([209.85.160.179]:35452 "EHLO mail-yk0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752759AbbHWWKm (ORCPT ); Sun, 23 Aug 2015 18:10:42 -0400 MIME-Version: 1.0 In-Reply-To: <55D8B605.4040302@kernel.org> References: <1440054451-1223-1-git-send-email-javier@osg.samsung.com> <1440054451-1223-14-git-send-email-javier@osg.samsung.com> <20150820200912.GA2866@deathstar> <55D64E80.4050502@osg.samsung.com> <20150820222906.GB28249@deathstar> <55D65937.6070909@osg.samsung.com> <55D8B605.4040302@kernel.org> From: Rob Herring Date: Sun, 23 Aug 2015 17:10:22 -0500 Message-ID: Subject: Re: [PATCH 13/18] iio: adc: mcp320x: Set struct spi_driver .of_match_table To: Jonathan Cameron Cc: Javier Martinez Canillas , Michael Welling , "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?= , Hartmut Knaack , "devicetree@vger.kernel.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 Content-Length: 2718 Lines: 72 On Sat, Aug 22, 2015 at 12:48 PM, Jonathan Cameron wrote: > On 20/08/15 23:48, Javier Martinez Canillas wrote: >> Hello Michael, >> >> On 08/21/2015 12:29 AM, Michael Welling wrote: >>> On Fri, Aug 21, 2015 at 12:02:40AM +0200, Javier Martinez Canillas wrote: >>>> 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). >>> >>> Well I have read it now. :) >>> >> >> Great :) >> >>>> >>>>> 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. >>>> >>> >>> Well then shouldn't the patch include adding the vendor to the compatible >>> string? >>> >> >> Well, I was talking in general. You are right that this specific driver does >> not have a vendor prefix for the compatible strings. This is incorrect >> according to the ePAPR document [0]. >> >> However, these compatible strings are already documented as a DT binding doc >> in Documentation/devicetree/bindings/iio/adc/mcp320x.txt so I don't know >> what is the correct thing to do in this situation. > Take the view the old version is wrong but needs to be supported and add also > the corrected strings + document them. > > cc'd The device tree list for any more comments on this. Agreed. Document both and mark the old one deprecated. Rob -- 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/