From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22BB9C433F4 for ; Tue, 28 Aug 2018 08:17:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 736012083C for ; Tue, 28 Aug 2018 08:17:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 736012083C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=macq.eu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727147AbeH1MIZ (ORCPT ); Tue, 28 Aug 2018 08:08:25 -0400 Received: from smtp2.macqel.be ([109.135.2.61]:64532 "EHLO smtp2.macqel.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726997AbeH1MIY (ORCPT ); Tue, 28 Aug 2018 08:08:24 -0400 X-Greylist: delayed 381 seconds by postgrey-1.27 at vger.kernel.org; Tue, 28 Aug 2018 08:08:24 EDT Received: from localhost (localhost [127.0.0.1]) by smtp2.macqel.be (Postfix) with ESMTP id 88832130D3E; Tue, 28 Aug 2018 10:11:34 +0200 (CEST) X-Virus-Scanned: amavisd-new at macqel.be Received: from smtp2.macqel.be ([127.0.0.1]) by localhost (mail.macqel.be [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9rCtmRw3-dan; Tue, 28 Aug 2018 10:11:32 +0200 (CEST) Received: from frolo.macqel.be (frolo.macqel [10.1.40.73]) by smtp2.macqel.be (Postfix) with ESMTP id E1AE2130D0E; Tue, 28 Aug 2018 10:11:32 +0200 (CEST) Received: by frolo.macqel.be (Postfix, from userid 1000) id B7AD2DF007A; Tue, 28 Aug 2018 10:11:32 +0200 (CEST) Date: Tue, 28 Aug 2018 10:11:32 +0200 From: Philippe De Muyter To: Luca Ceresoli Cc: Sakari Ailus , linux-media@vger.kernel.org, Leon Luo , Mauro Carvalho Chehab , Sakari Ailus , linux-kernel@vger.kernel.org, hverkuil@xs4all.nl, laurent.pinchart@ideasonboard.com Subject: Re: [PATCH 3/7] media: imx274: don't hard-code the subdev name to DRIVER_NAME Message-ID: <20180828081132.GA17946@frolo.macqel> References: <20180824163525.12694-1-luca@lucaceresoli.net> <20180824163525.12694-4-luca@lucaceresoli.net> <20180825144915.tq7m5jlikwndndzq@valkosipuli.retiisi.org.uk> <799f4d1a-b91d-0404-7ef0-965d123319da@lucaceresoli.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <799f4d1a-b91d-0404-7ef0-965d123319da@lucaceresoli.net> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Sakari and Luca, On Sun, Aug 26, 2018 at 10:41:13PM +0200, Luca Ceresoli wrote: > Hi Sakari, > > On 25/08/2018 16:49, Sakari Ailus wrote: > > Hi Luca, > > > > On Fri, Aug 24, 2018 at 06:35:21PM +0200, Luca Ceresoli wrote: > >> Forcibly setting the subdev name to DRIVER_NAME (i.e. "IMX274") makes > >> it non-unique and less informative. > >> > >> Let the driver use the default name from i2c, e.g. "IMX274 2-001a". > >> ... > > > > This ends up changing the entity as well as the sub-device name which may > > well break applications. > > Right, unfortunately. > > > On the other hand, you currently can't have more > > than one of these devices on a media device complex due to the name being > > specific to a driver, not the device. > > > > An option avoiding that would be to let the user choose by e.g. through a > > Kconfig option would avoid having to address that, but I really hate adding > > such options. > > I agree adding a Kconfig option just for this would be very annoying. > However I think the issue affects a few other drivers (sr030pc30.c and > s5c73m3-core.c apparently), thus maybe one option could serve them all. > > > I wonder what others think. If anyone ever needs to add another on a board > > so that it ends up being the part of the same media device complex > > (likely), then changing the name now rather than later would be the least > > pain. In this case I'd be leaning (slightly) towards accepting the patch > > and hoping there wouldn't be any fallout... I don't see any board (DT) > > containing imx274, at least not in the upstream kernel. > > I'll be OK with either decision. Should we keep it as is, then I think a > comment before that line would be appropriate to clarify it's not > correct but it is kept for backward userspace compatibility. This would > help avoid new driver writers doing the same mistake, and prevent other > people to send another patch like mine. Would it be acceptable to accept Luca's patch but add a dev_info message indicating the old and the new name, so that at least if the user notices a problem he'll find an informative message helping him to fix his config ? This dev_info message could even be standardized to be usable for other drivers with only the names changed. Philippe -- Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles