From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E759936BCC2 for ; Wed, 1 Apr 2026 07:51:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775029913; cv=none; b=Vfy4qd6zqUhnP+XAN0n5jqXTPrWGhWOcTXQ5QZ6YeLok9IUUaRcFzQOLeQHQeBKv1VB3HBRKu61FM4Bi30ioDUfhKZky88oFJqIlSvEn69YWsV61qwAEPQYwdaF9QApFMXWBqi23gckZ97NzM/S5CYkkmZGZzcRAE1Ba2fkd9Bc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775029913; c=relaxed/simple; bh=nGkaXP9XPQ+gkqH3UjHw265YM7bUq5L6id6igkjNKAU=; h=Mime-Version:Content-Type:Date:Message-Id:Subject:Cc:To:From: References:In-Reply-To; b=NzNEPb+lxqRoVGD/R7S6unuED8ovmqT9y4U0WHyHPzkZGyS6C2ArHBkxdJVnX9a1KFU9bEPjzC8FND8yD0pFCsrgSiR5Ta0fxzArx+SpYcXc8t4gK5eHLdlPrsqsWq85Gyz9sAeCQagCSh/hKtGYOnWL3ESlqTDOXKSpj1yYt0U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=jWk6Fnxj; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="jWk6Fnxj" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 15C8A4E42894; Wed, 1 Apr 2026 07:51:49 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id D6800602BF; Wed, 1 Apr 2026 07:51:48 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 48FAD104512AE; Wed, 1 Apr 2026 09:51:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1775029906; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=uT7sfHLuVPP3pEA5gLyzkA2Moxay1BQG8R6pq63tpdQ=; b=jWk6FnxjhGu2HcFc6zGL1OGj6IL5Zs7/Fl2Q686nDDtC28o/cBxZ0B5lnUgMb37DGCL/Uk rAjgfnUYQptI93q8MJ004w4xbAb0+iSNuMQn9BXWLFmJ0E+TwO5ks3CpK3aS4oCSxnCKRU QXYU3b5/LY3B0NwZS5vOTSmfYsZ2wWNaStVw9fQjBhfWXkjntmhhB5fsLoGxV9ESHBvuX4 CJxuDmkRLmRKssspV9E+L5j8UlAdYdS0YRJjLFpjzXOjdxfqUwFKGxr09Kpv1Y0sAvTKxM aadA789/nx2gmTp7hmC5i/xOnlgXKhPoYHWGW6hvDd7p6XHfczcQNgIyNyDbzg== Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Wed, 01 Apr 2026 09:51:32 +0200 Message-Id: Subject: Re: [PATCH 7/8] drm/bridge: imx8mp-hdmi-tx: add an hdmi-connector when missing using a DT overlay at boot time Cc: "Kory Maincent (TI.com)" , =?utf-8?q?Herv=C3=A9_Codina?= , "Hui Pu" , "Ian Ray" , "Thomas Petazzoni" , , , , , , "Adam Ford" , "Alexander Stein" , "Anson Huang" , "Christopher Obbard" , "Daniel Scally" , "Emanuele Ghidoli" , "Fabio Estevam" , "Francesco Dolcini" , "Frieder Schrempf" , "Gilles Talis" , =?utf-8?q?Goran_Ra=C4=91enovi=C4=87?= , "Heiko Schocher" , "Joao Paulo Goncalves" , "Josua Mayer" , "Kieran Bingham" , "Marco Felsch" , "Martyn Welch" , "Oleksij Rempel" , "Peng Fan" , "Philippe Schenker" , "Richard Hu" , "Shengjiu Wang" , "Stefan Eichenberger" , "Vitor Soares" To: "Liu Ying" , "Marek Vasut" , "Stefan Agner" , "Maarten Lankhorst" , "Maxime Ripard" , "Thomas Zimmermann" , "David Airlie" , "Simona Vetter" , "Frank Li" , "Sascha Hauer" , "Pengutronix Kernel Team" , "Fabio Estevam" , "Andrzej Hajda" , "Neil Armstrong" , "Robert Foss" , "Laurent Pinchart" , "Jonas Karlman" , "Jernej Skrabec" , "Rob Herring" , "Saravana Kannan" From: "Luca Ceresoli" X-Mailer: aerc 0.20.1 References: <20260320-drm-lcdif-dbanc-v1-0-479a04133e70@bootlin.com> <20260320-drm-lcdif-dbanc-v1-7-479a04133e70@bootlin.com> <544112ab-8ca0-4622-b680-233457198e3e@nxp.com> <5f06ea5a-5388-440f-91d6-cebb0bee0a88@nxp.com> <9a6e74ed-d4ab-4f11-ab17-25e1a2b64b2d@nxp.com> <246ca728-1be6-4dd9-b228-7d99f28e1abe@nxp.com> In-Reply-To: <246ca728-1be6-4dd9-b228-7d99f28e1abe@nxp.com> X-Last-TLS-Session-Version: TLSv1.3 Hello Liu, On Wed Apr 1, 2026 at 8:45 AM CEST, Liu Ying wrote: >>>>>> Boards with a different connector should describe the connector in t= he >>>>>> device tree, if they need to instantiate the exact type. >>>> >>>> I think this is the only valid solution. It's very easy to do, nothing= new >>>> to invent. >>>> >>>> Maybe on top of that we could add a warning when the overlay is applie= d, >>>> e.g. "imx8mp-hdmi-tx used without a connector described in device tree= ; >>>> adding a type A connector as a fallback; please add a valid descriptio= n to >>>> your device tree". >>> >>> I'd say this doesn't sound a bad idea but I hope the message is clear a= nd >>> short. >> >> What about: >> >> Connector description not found in device tree, please add one. Fallin= g back to Type A. > > Maybe: > Please add a hdmi-connector DT node for imx8mp-hdmi-tx. A fixup node in t= ype a is added for now. > >> >>>> Maybe pointing to a TODO entry in the documentation. >>> >>> To parameterize the HDMI connector type? If so, I'm okay with that. >> >> I was meaning a TODO entry to suggest people to add a connector descript= ion >> to the dts. E.g., expanding on the above suggested warning: >> >> Connector description not found in device tree, please add one. See ht= tps://docs.kernel.org/gpu/todo.html#<...> >> >> And of course adding a TODO entry describing what one needs to do (add a= n >> hdmi-connector node and link it to port@1 of the hdmi-tx). >> >> The drawback of the TODO is that items in todo.rst are supposed to be >> removed eventually when done in the code, but this one cannot be removed >> until some kernels printing the above logging message will be around, >> i.e. potentially for decades. > > Not a big fan of adding a TODO entry, because those DT blobs without a > hdmi-connector node could be out there forever, meaning the added TODO > entry can never be removed. > >> >> So maybe the simplest solution is just the first warning message + a >> comment in the code right before the warning line, so it easily found wi= th >> grep or a web search by who sees the warning. > > +1. Agreed. I've already sent v2, so I'll queue this for v3. Luca -- Luca Ceresoli, Bootlin Embedded Linux and Kernel engineering https://bootlin.com