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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8BE5C433EF for ; Fri, 1 Apr 2022 18:48:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344949AbiDASuZ (ORCPT ); Fri, 1 Apr 2022 14:50:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351387AbiDASuY (ORCPT ); Fri, 1 Apr 2022 14:50:24 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4CA63DDFC for ; Fri, 1 Apr 2022 11:48:33 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 1A8D62F7; Fri, 1 Apr 2022 20:48:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1648838911; bh=dujnelcPNk6p4CPVgNhMrG7u9/pxO/a8Ef1tc/FG5g8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=C448RAHkb851knPnWOoU22kqCqcMUdrSIT3Y4q7CH3s994gbPtVuGPfDqeLYp4+zd utH2X1f/E1dP4O4zB4ACZY6bxCJ5dRmH75CcgMQSHj1LFRpwOsuhtH8vvqrRQ2LFvf wlEg+JOPFA2JZfVDZ//EBsfNPkmVMedLFeYNLoPY= Date: Fri, 1 Apr 2022 21:48:28 +0300 From: Laurent Pinchart To: Rob Herring Cc: Marek Vasut , Maxime Ripard , Neil Armstrong , Andrzej Hajda , Daniel Vetter , David Airlie , devicetree@vger.kernel.org, Jagan Teki , Jernej Skrabec , Jonas Karlman , Robert Foss , Frank Rowand , dri-devel Subject: Re: [PATCH] dt-bindings: display: bridge: Drop requirement on input port for DSI devices Message-ID: References: <20220323154823.839469-1-maxime@cerno.tech> <1fddec5f-5fb3-4ea0-a1e5-9d1b9e54de81@denx.de> <30ea889f-f65e-e887-e230-935d6207c919@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Fri, Apr 01, 2022 at 01:33:15PM -0500, Rob Herring wrote: > On Fri, Apr 1, 2022 at 1:25 PM Marek Vasut wrote: > > On 4/1/22 20:21, Rob Herring wrote: > > > On Fri, Apr 1, 2022 at 1:06 PM Marek Vasut wrote: > > >> On 4/1/22 19:34, Rob Herring wrote: > > >>> On Fri, Apr 01, 2022 at 03:22:19AM +0200, Marek Vasut wrote: > > >>>> On 4/1/22 01:52, Rob Herring wrote: > > >>>>> On Wed, 23 Mar 2022 16:48:23 +0100, Maxime Ripard wrote: > > >>>>>> MIPI-DSI devices, if they are controlled through the bus itself, have to > > >>>>>> be described as a child node of the controller they are attached to. > > >>>>>> > > >>>>>> Thus, there's no requirement on the controller having an OF-Graph output > > >>>>>> port to model the data stream: it's assumed that it would go from the > > >>>>>> parent to the child. > > >>>>>> > > >>>>>> However, some bridges controlled through the DSI bus still require an > > >>>>>> input OF-Graph port, thus requiring a controller with an OF-Graph output > > >>>>>> port. This prevents those bridges from being used with the controllers > > >>>>>> that do not have one without any particular reason to. > > >>>>>> > > >>>>>> Let's drop that requirement. > > >>>>>> > > >>>>>> Signed-off-by: Maxime Ripard > > >>>>>> --- > > >>>>>> .../devicetree/bindings/display/bridge/chipone,icn6211.yaml | 1 - > > >>>>>> .../devicetree/bindings/display/bridge/toshiba,tc358762.yaml | 1 - > > >>>>>> 2 files changed, 2 deletions(-) > > >>>>>> > > >>>>> > > >>>>> I tend to agree with port@0 not being needed and really like > > >>>>> consistency. > > >>>> > > >>>> The consistent thing to do would be to always use port@0 and OF graph, no ? > > >>> > > >>> I guess it depends how wide our scope for consistency is. Just DSI bus > > >>> controlled bridges? DSI panels? All bridges and panels? Any panel > > >>> without a control interface has the same dilemma as those can be a child > > >>> of the display controller (or bridge) and not even use OF graph. > > >> > > >> I would likely opt for the OF graph in all cases, panels, bridges, > > >> controllers. Then it would be consistent. > > >> > > >>> All simple panels don't require 'port' either. That's presumably only > > >>> consistent because we made a single schema. I'd assume 'non-simple' > > >>> panels with their own schema are not consistent. > > >> > > >> Maybe we would start requiring that port even for simple panels ? > > >> The port is physically there on that panel after all. > > > > > > Fix this in all the dts files and then I'll agree. Though I think this > > > ship has already sailed. I'd like to someday get to platforms without > > > warnings and not just keep adding new warnings. > > > > I doubt we can fix existing DTs, but can we at least require it for new > > DTs ? > > We don't have any way to do that currently and get to warning free for > all DTs. We'd need to be able to disable specific checks for specific > DTs. I've thought about it, but haven't come up with a way to do it. I think Marek may have meant new bindings. While I do agree that inconsistencies in sources can cause new submissions to blindly copy mistakes, it shouldn't be a reason in itself to carry historical binding design mistakes in new bindings. -- Regards, Laurent Pinchart