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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 20F9BC25B76 for ; Mon, 3 Jun 2024 07:42:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: MIME-Version:List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe :List-Id:In-Reply-To:References:Cc:Subject:To:From:Message-Id:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3+Wgh7XW2gdYJzyIVzc/PgGpA+yZT7XO5T1oa8aUqS4=; b=d5wfHTPkxDycjSiEELAsNbT8sU Ah0ufFH893F8jcVCPtamq4qB3KVqOhbiHjZ+U5eyJseYn4GxUDwH9VD/8/DvbcDdM94i1VeQSF1tc nZ5ZmI5jzYi/YV/6/uNd1eNmtUq86hipbjP1rVx1NyMS6fEm8GEeXZuJzMNgq+dIaRTlO3ajhSRJs NiarE+HLLJxjgeXU3U6EnTj55dOXdCMrdFT4VYiWBTfM/MBLxzyHLhW0/mYcCYXm9UU+RAjvBbPaT JMrzcOsqRO4pFakKzbxp4ucERGZqMbuNkQN1/KRC4q1jrgNZHzb193M9DRTqXrNMt2b2Ycz3gF5WF Ix9beacg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sE2L9-0000000FwHa-3kRa; Mon, 03 Jun 2024 07:42:47 +0000 Received: from 0001.3ffe.de ([159.69.201.130] helo=mail.3ffe.de) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sE2L7-0000000FwF0-3IAu; Mon, 03 Jun 2024 07:42:47 +0000 Received: from localhost (unknown [213.135.10.150]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.3ffe.de (Postfix) with ESMTPSA id 30CEA136A; Mon, 3 Jun 2024 09:42:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2022082101; t=1717400554; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:content-type:content-type:in-reply-to:in-reply-to: references:references; bh=l/sXJWAR9U+t8PuJjd67PbuHh01c02nSqxd7Y8bCUpM=; b=mKfgfIw0rVXzUB2hP0B2WxtTyKBz9VHQ5GW0H/acJGDGO7XYNyllK5U2aU0laMQOncMNxb 63+o3L3cwsC9BhAZl30ZY1W9aOEIKA0BadMQEvJfy28XQnJ6+Ag1UrmyyEpsPO+vKug+un VIOmTj0ewguhvmUIc59KofVhqUsJ34y4Vz9XPQBBUgMTDGUnRQXFk6+nrb3CaP/4hXmPHs bCgss0RdUhLImzMiLhXc+o9Y5G8Q2Shz99/HZYYA3JDlD/Bysg/DzDX2nPvCthzELAPQCH N2RKaKynB4Z4wd5LO7zIxX5MplhmoRaMzAQ9NZNTakTdQUCwqGCiLUgX0z004g== Date: Mon, 03 Jun 2024 09:42:31 +0200 Message-Id: From: "Michael Walle" To: "AngeloGioacchino Del Regno" , Subject: Re: [PATCH v4 3/3] drm/mediatek: Implement OF graphs support for display paths Cc: , , , , , , , , , , , , , , , , , , , , X-Mailer: aerc 0.16.0 References: <20240516081104.83458-1-angelogioacchino.delregno@collabora.com> <20240516081104.83458-4-angelogioacchino.delregno@collabora.com> <84cd0ac7-99d9-42cb-af79-a0fba09c1ebb@collabora.com> In-Reply-To: <84cd0ac7-99d9-42cb-af79-a0fba09c1ebb@collabora.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240603_004246_040648_00155141 X-CRM114-Status: GOOD ( 18.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4306505803739515774==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============4306505803739515774== Content-Type: multipart/signed; boundary=3ed5ea633b485a24b502befa1bea475237ec606cb99637397be66d7a74b8; micalg=pgp-sha384; protocol="application/pgp-signature" --3ed5ea633b485a24b502befa1bea475237ec606cb99637397be66d7a74b8 Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Hi Angelo, > >> Implement OF graphs support to the mediatek-drm drivers, allowing to > >> stop hardcoding the paths, and preventing this driver to get a huge > >> amount of arrays for each board and SoC combination, also paving the > >> way to share the same mtk_mmsys_driver_data between multiple SoCs, > >> making it more straightforward to add support for new chips. > >=20 > > paths might be optional, see comment in mtk_drm_kms_init(). But with > > this patch, you'll get an -EINVAL with a disabled path. See my > > proposals how to fix that below. > > I might not be understanding the reason behind allowing that but, per my = logic, if > a board does have a path, then it's written in devicetree and enabled - o= therwise, > it should not be there at all, in principle. > > > Can you explain a bit more extensively the reason(s) why we need to accou= nt > for disabled paths? Paths should be (and this was already supported before this patch with the hardcoded paths) disabled with the status property. This way you can have a common board configuration where all the paths are already described but are disabled. An overlay (or maybe another dts variant) can then just enable the pipeline/output port by overwriting the status property. Also, this is the usual DT usage, as a node with status =3D "disabled" should just be skipped. Without handling this, the current code will return -EINVAL during probe (IIRC, my vacation might have reset my memory :o). -michael --3ed5ea633b485a24b502befa1bea475237ec606cb99637397be66d7a74b8 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iKcEABMJAC8WIQTIVZIcOo5wfU/AngkSJzzuPgIf+AUCZl1z6BEcbWljaGFlbEB3 YWxsZS5jYwAKCRASJzzuPgIf+EuiAYCiS0ktYeqW3WREzRyRaWz/fZqG9E+chTLp Eq2F71PR2kPsrQjcJqjw9P8PJP1Tb7IBf1Xo00KNX/YZCxZd7B2+oCO6cjri7/ym ZBbCHMlAM8XqJvXrDFXC1OxZkA8QuPDVng== =F2kN -----END PGP SIGNATURE----- --3ed5ea633b485a24b502befa1bea475237ec606cb99637397be66d7a74b8-- --===============4306505803739515774== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============4306505803739515774==--