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 327A7CCF9E0 for ; Tue, 28 Oct 2025 10:17:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 97EC710E37D; Tue, 28 Oct 2025 10:16:59 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.b="pWDCE+fn"; dkim-atps=neutral Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) by gabe.freedesktop.org (Postfix) with ESMTPS id DAE0510E376 for ; Tue, 28 Oct 2025 10:16:48 +0000 (UTC) Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 64568C0BE9C; Tue, 28 Oct 2025 10:16:27 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id A16BC606AB; Tue, 28 Oct 2025 10:16:47 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 126151179B191; Tue, 28 Oct 2025 11:16:43 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1761646606; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=vdYNl+jUov2A+6UN1VU5gxICmAEu5JVGl0RzN3EysYI=; b=pWDCE+fnq8i9VUHvOlzUK8F0XX42hsC0TBdhfPAc52Yq0huRzaEVKhDRn849CHnXrxmYl6 nyow7QVbg+7gID4HfgcCAZChnRystZb9Jyn9GE3xyOgLzH4kDHKnnMsImZXTOAeSx97US+ VE+L3tB48aVLcFz96hOWoreKCYkN05t8k0WG420X8vHVKWSOBHJnwgwc0zWpOZ9cerIcZz IpbdZ5Skw7bSZftXLEoZm3JWMTf+SHoCnk2SBmPyrv8hUAc1Hx5N+pqhi5ceWJqwlYkBmB aGDwdiybj15TolwWmRF/3myX5YPvOtInsnUnCkV9hzCRK3Bd7UEJaCBv3aibJw== From: Luca Ceresoli Date: Tue, 28 Oct 2025 11:15:46 +0100 Subject: [PATCH v3 5/6] drm/bridge: add warning for bridges using neither devm_drm_bridge_alloc() nor drm_bridge_add() MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251028-b4-drm-bridge-alloc-add-before-attach-v3-5-bb8611acbbfb@bootlin.com> References: <20251028-b4-drm-bridge-alloc-add-before-attach-v3-0-bb8611acbbfb@bootlin.com> In-Reply-To: <20251028-b4-drm-bridge-alloc-add-before-attach-v3-0-bb8611acbbfb@bootlin.com> To: Alain Volmat , 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 , Andy Yan 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 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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/hlf4wdopapxnh4rekl5s3kvoi6egaga3lrjfbx6r223ar3txri@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..8f355df883d8ac8de9d361ec302f4ccbf3bca0d6 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, struct drm_bridge *bridge, if (!encoder || !bridge) return -EINVAL; + 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"); -- 2.51.0