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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 90848C48BD1 for ; Fri, 11 Jun 2021 12:56:25 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 1EF59613B8 for ; Fri, 11 Jun 2021 12:56:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1EF59613B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 972026E7FE; Fri, 11 Jun 2021 12:56:24 +0000 (UTC) Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by gabe.freedesktop.org (Postfix) with ESMTPS id EDE3D6E7FE for ; Fri, 11 Jun 2021 12:56:22 +0000 (UTC) Received: from maud (unknown [IPv6:2600:8800:8c04:8c00::6334]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: alyssa) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id EAA2F1F4468F; Fri, 11 Jun 2021 13:56:09 +0100 (BST) Date: Fri, 11 Jun 2021 08:56:04 -0400 From: Alyssa Rosenzweig To: Liviu Dudau Subject: Re: [PATCH v3] Documentation: gpu: Mention the requirements for new properties Message-ID: References: <20210610174731.1209188-1-maxime@cerno.tech> <20210611120309.2b5eb4htupv5ss32@e110455-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210611120309.2b5eb4htupv5ss32@e110455-lin.cambridge.arm.com> 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: Haneen Mohammed , Alexandre Belloni , Linux Doc Mailing List , Xinliang Liu , Daniel Vetter , Edmund Dea , Alexandre Torgue , dri-devel , Russell King , Melissa Wen , Tomi Valkeinen , Thierry Reding , Laurent Pinchart , Benjamin Gaignard , Anitha Chrisanthus , Daniel Vetter , Steven Price , Sam Ravnborg , Jyri Sarha , Jerome Brunet , Marek Vasut , Joonyoung Shim , Qiang Yu , Krzysztof Kozlowski , Kevin Hilman , Neil Armstrong , Alyssa Rosenzweig , Xinwei Kong , Jonathan Hunter , David Airlie , Ludovic Desroches , Kieran Bingham , VMware Graphics , NXP Linux Team , Ben Skeggs , Chun-Kuang Hu , Maxime Coquelin , Jonas Karlman , Martin Blumenstingl , Chen Feng , Sascha Hauer , Alison Wang , Roland Scheidegger , Andrzej Hajda , Hans de Goede , Maxime Ripard , Rodrigo Vivi , Matthias Brugger , Nicolas Ferre , Chen-Yu Tsai , Sean Paul , Thomas Zimmermann , Paul Cercueil , Jernej Skrabec , Huang Rui , Rodrigo Siqueira , Hyun Kwon , Boris Brezillon , Andrew Jeffery , Yannick Fertr e , Jonathan Corbet , Seung-Woo Kim , Sandy Huang , Robert Foss , Joel Stanley , Tomeu Vizoso , Kyungmin Park , Noralf Tr??nnes , Philippe Cornu , Pengutronix Kernel Team , Alex Deucher , Tian Tao , Oleksandr Andrushchenko , Shawn Guo , Christian K??nig , Gerd Hoffmann Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > What I'm expected to see in the future is new functionality that gets implemented by > one hardware vendor and the kernel developers trying to enable that for userspace. It > could be that the new property is generic, but there is no way of testing that on > more than one implementation yet, so I'd say we are generous calling it "standard > property". When the second or third hardware vendor comes along and starts supporting > that property with their own set of extra requirements, then we can call it > "standard". Then comes the effort cost: would it be easier to start with a vendor > property that only the vendor needs to support (and can submit patches into the > compositors to do so) and when the standard property gets added moves to that, or > should we start with a generic property that gets implemented by the compositors > (maybe, but then only one vendor supports it) and then later when we actually > standardise the property we will have to carry backwards compatibility code in the > kernel to handle the old behaviour for old userspace? My proposal to Maxime was for > the former option to be reflected in the documentation, but I would like to hear your > thoughts. Just my 2c - if the mainline kernel isn't willing to commit to a feature for upstream userspace to use, why does that feature belong in the kernel at all? I don't see much value in exposing hardware for the sake of exposing it when, practically, Linux userspace /can't/ use it as-is. Might these vendor properties be used on downstream Android userspaces? That's not generally an upstream goal to support.