Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751462AbdH1PHa (ORCPT ); Mon, 28 Aug 2017 11:07:30 -0400 Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:40412 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751232AbdH1PH2 (ORCPT ); Mon, 28 Aug 2017 11:07:28 -0400 Date: Mon, 28 Aug 2017 18:07:25 +0300 From: Sakari Ailus To: Pavel Machek Cc: Sebastian Reichel , pali.rohar@gmail.com, kernel list , linux-arm-kernel , linux-omap@vger.kernel.org, tony@atomide.com, khilman@kernel.org, aaro.koskinen@iki.fi, ivo.g.dimitrov.75@gmail.com, patrikbachan@gmail.com, serge@hallyn.com, abcloriens@gmail.com Subject: Re: [PATCH] nokia n900: update dts with camera support Message-ID: <20170828150725.nvrr2c3a2lir5xic@valkosipuli.retiisi.org.uk> References: <20170810204923.GA18442@amd> <20170814201950.sbtyuksn3ntuigyp@valkosipuli.retiisi.org.uk> <20170815220349.GA15441@amd> <20170816205332.rqcuenvuxfs5jvuw@earth> <20170816205915.GA5386@atrey.karlin.mff.cuni.cz> <20170816212343.hfd4azb4dq2qrlkc@valkosipuli.retiisi.org.uk> <20170817000845.agkcuvqaheejm33j@earth> <20170828135959.GA32560@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170828135959.GA32560@amd> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1778 Lines: 50 Hi Pavel, On Mon, Aug 28, 2017 at 03:59:59PM +0200, Pavel Machek wrote: > Hi! > > > > > Well, strobe property above already uses = <0>/<1> format, as do > > > > others. > > > > > > > Problem with "false = property does not exist" is that you don't know > > > > if it is "someone forgot to define it" or "someone made a typo" or > > > > "dts is too old to know about this property" or "the property indeed > > > > should be false"... > > > > > > As this is an established practice, I think we should follow it for bool > > > properties. > > > > Yes it's common practice, there is also device_property_read_bool() > > to get the value. > > > > > We could change the existing ones, too, and leave some extra checks in > > > place to handle old dtbs. > > > > The following should be downward compatible: > > > > var = read_bool(); > > if (var && !read_int()) > > var = false; > > > > Btw. DT people should be CC'd for DT binding additions/changes. > > Ok, so for now we do crc=1 by default. Now we'd like to have crc > support configurable in the dts. But if we just introduce "crc;" > option, it will break old dts users. We could introduce "no-crc;" and > that would work in this particular case, but will break when we want > different defaults at different devices. > > Anyway, introducing "no-crc;" seems pretty ugly to me. I'd rather do > "crc=<0>;", in a similar way we handle other options now. The same issue actually exists for CSI-2: the CRC is typically enabled and I think you can at least disable the check (in OMAP3 ISP). Do we have a need to disable it at the moment for any purpose? I think I've seen this was disabled somewhere but it may just as well be a thoughtlessly written configuration. -- Regards, Sakari Ailus e-mail: sakari.ailus@iki.fi