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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 05655C43603 for ; Tue, 17 Dec 2019 23:11:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C54172176D for ; Tue, 17 Dec 2019 23:11:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="XlT2bU5R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbfLQXLv (ORCPT ); Tue, 17 Dec 2019 18:11:51 -0500 Received: from perceval.ideasonboard.com ([213.167.242.64]:56952 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725886AbfLQXLv (ORCPT ); Tue, 17 Dec 2019 18:11:51 -0500 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 0023A9BF; Wed, 18 Dec 2019 00:11:48 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1576624309; bh=3pXofW/87TuK7bgMn6IvC70DbbQkK6YEsubNMznQLGw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XlT2bU5R9uYScf5C60rZXMiFTNvL0veueEEQEsL2C0J5qPnlW4QMYPUD2rvrtbYdx sVDWZmWGGlkNFCaXFNWAf5E4o5H+xV+hPpnJeD9hwKYq0gSOU3Coz+24SeH6ygGU0r t0CECOV2oF67iTOZK8QBSWLK5+Imj6puIZ6ofsyw= Date: Wed, 18 Dec 2019 01:11:38 +0200 From: Laurent Pinchart To: Geert Uytterhoeven Cc: Kieran Bingham , Simon Horman , Sergei Shtylyov , Linux-Renesas , David Airlie , Daniel Vetter , "open list:DRM DRIVERS FOR RENESAS" , open list Subject: Re: [PATCH] drm: rcar-du: Add r8a77980 support Message-ID: <20191217231138.GF4874@pendragon.ideasonboard.com> References: <20190911192502.16609-1-kieran.bingham+renesas@ideasonboard.com> <70b94265-69f3-d18f-1b67-b5b814723b1b@cogentembedded.com> <20190913082129.lvusbp6pbcayqh5r@verge.net.au> <20190913090359.GC29992@pendragon.ideasonboard.com> <2eeacacc-f190-4ba8-32bc-b4103b41db46@ideasonboard.com> <20191213004812.GA27328@pendragon.ideasonboard.com> <19cb3d1c-6910-4bec-13bb-adb875ddd077@ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org On Mon, Dec 16, 2019 at 11:37:00AM +0100, Geert Uytterhoeven wrote: > On Mon, Dec 16, 2019 at 10:47 AM Kieran Bingham wrote: > > On 13/12/2019 00:48, Laurent Pinchart wrote: > >> On Mon, Dec 09, 2019 at 12:41:07PM +0000, Kieran Bingham wrote: > >>> On 13/09/2019 10:03, Laurent Pinchart wrote: > >>>> On Fri, Sep 13, 2019 at 10:21:29AM +0200, Simon Horman wrote: > >>>>> On Thu, Sep 12, 2019 at 01:00:41PM +0300, Sergei Shtylyov wrote: > >>>>>> On 11.09.2019 22:25, Kieran Bingham wrote: > >>>>>> > >>>>>>> Add direct support for the r8a77980 (V3H). > >>>>>>> > >>>>>>> The V3H shares a common, compatible configuration with the r8a77970 > >>>>>>> (V3M) so that device info structure is reused. > >>>>>> > >>>>>> Do we really need to add yet another compatible in this case? > >>>>>> I just added r8a77970 to the compatible prop in the r8a77980 DT. That's why > >>>>>> a patch like this one didn't get posted by me. > >>>>> > >>>>> The reason for having per-SoC compat strings is that the IP blocks > >>>>> are not versioned and while we can observe that there are similarities > >>>>> between, f.e. the DU on the r8a77970 and r8a77980, we can't be certain that > >>>>> differences may not emerge at some point. By having per-SoC compat strings > >>>>> we have the flexibility for the driver to address any such differences as > >>>>> the need arises. > >>>>> > >>>>> My recollection is that this scheme has been adopted for non-versioned > >>>>> Renesas IP blocks since June 2015 and uses of this scheme well before that. > >>>> > >>>> Sure, but we could use > >>>> > >>>> compatible = "renesas,du-r8a77980", "renesas,du-r8a77970"; > > > > We already do in arch/arm64/boot/dts/renesas/r8a77980.dtsi. > > > > However that is the *only* non r8a77980 reference in the file so it, > > itself looks *very* much out of place. > > > > > > Furthermore, the main purpose of this patch is that we clearly document > > the driver as supporting the r8a77980 in the bindings (No mention that > > you must use the ..970 binding), yet in actual fact - the driver could > > not currently support loading a device with the following compatible: > > > > compatible = "renesas,du-r8a77980"; > > > > > >>>> in DT without updating the driver. If the r8a77980 turns out to be > >>>> different, we'll then update the driver without a need to modify DT. I'm > >>>> fine either way, so > >>>> > >>>> Reviewed-by: Laurent Pinchart > >>> > >>> Thanks, > >>> > >>> This patch has an RB tag from you, and Simon, but alas I don't believe > >>> it has been picked up in your drm/du/next branch. > >>> > >>> Is this patch acceptable? Or do I need to repost? > >> > >> Could you just confirm I should apply this patch, and not go for the > >> alternative proposal above ? > > > > I believe the alternative proposal above is what we have today isn't it? > > > > > > Yes, I do believe we should apply this patch. > > +1. > > I'm waiting for the driver part to go upstream, so I can apply the DTS patch. > Note that this will lead to a messy situation in LTS, as the DTS patch will > likely be backported, so the driver part must be backported, too. Reviewed-by: Laurent Pinchart and taken in my tree. > > I'm going to assume you haven't read the other arguments on this thread > > so I'll paste them here: > > Thanks for recollecting! ;-) -- Regards, Laurent Pinchart