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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 75CABC47DDB for ; Tue, 23 Jan 2024 15:15:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C0B8210EE12; Tue, 23 Jan 2024 15:15:15 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id A201610EE9D for ; Tue, 23 Jan 2024 15:15:14 +0000 (UTC) Received: from pendragon.ideasonboard.com (89-27-53-110.bb.dnainternet.fi [89.27.53.110]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 971F51B9A; Tue, 23 Jan 2024 16:13:58 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1706022838; bh=KH0LvkdbK92DKVq5Xs21pvP2sw0RoJdUkpHOytWRwAM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TCd0pyWC9KqbqCI5zJb9AcehuYWsPviIQ8dVRw9+8vhPizbH1jRsgimEWeZwSEkIx Yo9P7jjIu/RQ1gb7JFZZs3yKMP8sY/IG2W6SJU8gcUorMxJLJLhXB6C+LOVLUKhGf8 /Hne88ti6bYq09pwpFMqJLe4kl/FqEZ96PiiD5q8= Date: Tue, 23 Jan 2024 17:15:10 +0200 From: Laurent Pinchart To: Sui Jingfeng Subject: Re: [PATCH 1/5] drm/bridge: Add drm_bridge_find_by_fwnode() helper Message-ID: <20240123151510.GM10679@pendragon.ideasonboard.com> References: <20240122163220.110788-1-sui.jingfeng@linux.dev> <20240122163220.110788-2-sui.jingfeng@linux.dev> <20240123011710.GA22880@pendragon.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Neil Armstrong , Thomas Zimmermann , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Maxime Ripard , Daniel Vetter , David Airlie Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Sui, On Tue, Jan 23, 2024 at 04:01:28PM +0800, Sui Jingfeng wrote: > On 2024/1/23 09:17, Laurent Pinchart wrote: > > On Tue, Jan 23, 2024 at 12:32:16AM +0800, Sui Jingfeng wrote: > >> Because ACPI based systems only has the fwnode associated, the of_node > >> member of struct device is NULL. To order to move things forward, we add > >> drm_bridge_find_by_fwnode() to extend the support. > >> > >> Signed-off-by: Sui Jingfeng > > > > Could we switch completely to fwnode, instead of maintaining the fwnode > > and OF options side-by-side ? > > The side-by-side approach allow us to migrate smoothly, But it increases the maintenance burden for the duration of the migration. I fear the migration would span years, with nobody really taking active care of it, and the OF and non-OF API will have a risk to diverge. > the main consideration is that the OF approach has been > works very well, it is flexible and very successful in > the embedded world. fwnode is a superset of OF, so I don't expect issues switching from OF to fwnode. For the non-OF, non-fwnode users, that's possibly a different question. > It seems that the fwnode API could NOT replace the OF > options completely. For example, the'of_device_id' and 'of_match_table' related things are always there, there Yes, and that's not a problem. OF drivers still use of_device_id and of_match_table, even if they use the fwnode API. No issue there. > are large well-established helpers and subroutines and > already formed as a standard. Some part of it may suffer > from backward compatibility problems. fwnode has been designed to offer the same API as OF for drivers. If something is missing, it can be raised with the maintainers. > So I want to leave some space to other programmers. > Maybe there are other programmers who feel that using > OF alone is enough for a specific problem(domain). -- Regards, Laurent Pinchart