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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 280ABC4CEC7 for ; Fri, 13 Sep 2019 09:04:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F3D612089F for ; Fri, 13 Sep 2019 09:04:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ZpddhD4W" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387641AbfIMJEK (ORCPT ); Fri, 13 Sep 2019 05:04:10 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:37348 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387513AbfIMJEJ (ORCPT ); Fri, 13 Sep 2019 05:04:09 -0400 Received: from pendragon.ideasonboard.com (bl10-204-24.dsl.telepac.pt [85.243.204.24]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 4DFB033A; Fri, 13 Sep 2019 11:04:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1568365447; bh=rBMYwvvqL3UBs1e6XFztfLKo2R8+K/g/9AvBH5KoQa0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZpddhD4Wm8ABiqJwt0ssORXff5gBpf5FQpURY4pipMIeYTH48wsk1C7BKluVcFLPD o997vSNrqnHnVX7h3Bvsr1PmmEL0fW+vae3NDxcXf4ASWNvaxP82EdHYVZ6rCOw30S KUI2lEiRSANkrnCFWRel45Xazuu0hEDEZRFgnB+E= Date: Fri, 13 Sep 2019 12:03:59 +0300 From: Laurent Pinchart To: Simon Horman Cc: Sergei Shtylyov , Kieran Bingham , linux-renesas-soc@vger.kernel.org, David Airlie , Daniel Vetter , "open list:DRM DRIVERS FOR RENESAS" , open list Subject: Re: [PATCH] drm: rcar-du: Add r8a77980 support Message-ID: <20190913090359.GC29992@pendragon.ideasonboard.com> References: <20190911192502.16609-1-kieran.bingham+renesas@ideasonboard.com> <70b94265-69f3-d18f-1b67-b5b814723b1b@cogentembedded.com> <20190913082129.lvusbp6pbcayqh5r@verge.net.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190913082129.lvusbp6pbcayqh5r@verge.net.au> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, 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"; 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 > > > Signed-off-by: Kieran Bingham > > Reviewed-by: Simon Horman -- Regards, Laurent Pinchart