From nobody Fri Oct 24 13:53:19 2025 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (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 9170B2877FC for ; Tue, 21 Oct 2025 21:01:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761080494; cv=none; b=Cym00M56fdF49sl8YNJCrW1viuXCG2H5iS2VVQRHnzFJH7vQ2JdZhxh0ZZwelEN2/ixSRRvLWQ0/3y/8i8sXbKfUW369BOZborNkdBg00CGqwy7aSZETau2CGio/JFyyNptXq4OZwosG1QU6GcqAlFsHuGaeRr9Tb2/byMpTuEQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761080494; c=relaxed/simple; bh=HNNcUjBlE2ezDrpCkSt1TAM29s3v4NT9WLUuWNfS/KY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ZDPbzY0oNTVh7W+soXxyS6NYe/aq5oDrtVxQ6E0Nr0bfT6gA4ck18vy4zObv9AKlQ+RitBs/dNMhFqR5QzTO3naMgh/ZGHuRI5d7LPqEeMZrwrbyYS0rodbBRlKjeCiFcFOaMMbkM6JwIX1TfHrZgCmsMsch3Qr9QCclJc1DZSE= 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=NZkWMIH9; arc=none smtp.client-ip=185.171.202.116 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="NZkWMIH9" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 43692C0B8A3; Tue, 21 Oct 2025 21:01:11 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id ED5AE60680; Tue, 21 Oct 2025 21:01:30 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id E13D6102F2421; Tue, 21 Oct 2025 23:01:27 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1761080490; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=vdYNl+jUov2A+6UN1VU5gxICmAEu5JVGl0RzN3EysYI=; b=NZkWMIH9WokjHWo6HtkBTaGYYhccTDAOhtx452H2om0J9x7UoSGu6t6YLJdfUFvn+9zPko NNrXwF+f0Bm9EyPzJCwbDDfmiV0dvryD/tdRmNfSGChRv32oEg9YHrwaa/cigmgjoCfece B0JXyM11qY6bQOMG8xEVjmlZhWUlORNEUifmnfxZMoeKp6/zQLyMpYagYOIWg63cRojBBW 4UNfzGeZmDvi3+w58ZsDSrr+cAsm7MMAWxaapfHB93SY6T104iqUSSp9IsVdYnqZmi84Dw 8Cf1+B4oKt7Op/03punHVioymNle3P6U71oQAhKXefwQwSqzbrwr7k58fR1cVg== From: Luca Ceresoli Date: Tue, 21 Oct 2025 23:00:48 +0200 Subject: [PATCH v2 5/5] drm/bridge: add warning for bridges using neither devm_drm_bridge_alloc() nor drm_bridge_add() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20251021-b4-drm-bridge-alloc-add-before-attach-v2-5-c17cc1bbff72@bootlin.com> References: <20251021-b4-drm-bridge-alloc-add-before-attach-v2-0-c17cc1bbff72@bootlin.com> In-Reply-To: <20251021-b4-drm-bridge-alloc-add-before-attach-v2-0-c17cc1bbff72@bootlin.com> To: Alain Volmat , Raphael Gallais-Pou , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Raphael Gallais-Pou Cc: Hui Pu , Thomas Petazzoni , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Luca Ceresoli X-Mailer: b4 0.14.2 X-Last-TLS-Session-Version: TLSv1.3 The correct sequence for bridge initialization is: 1. devm_drm_bridge_alloc() 2. drm_bridge_add() 3. drm_bridge_attach() For bridges missing either 1 or 2 there are warnings in place already, presenting an explanatory error message. Bridges missing both 1 and 2 would still face a poorly understandable message, as reported in a recent regression report [0]: WARNING: [...] at [...]/lib/refcount.c:25 drm_bridge_attach+0x2c/0x1dc ... Call trace: ... drm_bridge_attach ... Add a new warning to ensure an understandable message is logged in such cases. Use the same message and warning message already in place in drm_bridge_add(). [0] https://lore.kernel.org/all/hlf4wdopapxnh4rekl5s3kvoi6egaga3lrjfbx6r223= ar3txri@3ik53xw5idyh/ Signed-off-by: Luca Ceresoli --- This patch was added in v2 after having received regression report [0]. --- drivers/gpu/drm/drm_bridge.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 6dba601a056bb3cff8b8dd5b1ec46299235b2d85..8f355df883d8ac8de9d361ec302= f4ccbf3bca0d6 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -441,6 +441,9 @@ int drm_bridge_attach(struct drm_encoder *encoder, stru= ct drm_bridge *bridge, if (!encoder || !bridge) return -EINVAL; =20 + if (!bridge->container) + DRM_WARN("DRM bridge corrupted or not allocated by devm_drm_bridge_alloc= ()\n"); + if (list_empty(&bridge->list)) DRM_WARN("Missing drm_bridge_add() before attach\n"); =20 --=20 2.51.0