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 0A8B9C83F03 for ; Wed, 9 Jul 2025 16:00:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4FD9310E06E; Wed, 9 Jul 2025 16:00:10 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.b="Yt0hL0A5"; dkim-atps=neutral Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [217.70.183.194]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2537210E06E for ; Wed, 9 Jul 2025 16:00:07 +0000 (UTC) Received: by mail.gandi.net (Postfix) with ESMTPSA id 07039442B3; Wed, 9 Jul 2025 16:00:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1752076806; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=ssBjI9tL4zH8w0i7uvVdHfRAJbny2996+v1we4JsojM=; b=Yt0hL0A5JCbxElp+aK4twDKbv5rBzOAvDBr5sieeI2l0ZIKjiGySmBmrbrHgW03AAeOC/F y78N1zm0gziAlnNQLZUId+TUUTJkqzscZSFAXlmyQxdf97SY7Hh70fivn7cMewtJL1CFTv PWcXMPRFyiFmQDBsehNMUifjBVQ6L825AYSZZZL768FitOgxy/CKW6sY/qUOThxwYiY3c+ VsrUvM4CEW6ra3OJe9C0ovYh/eglxaUGvaIg7pyGYc3wQnVpPwWIKsGF7DXYlq/z+CAUH2 DDp9IVN+Dq9mQqplZ6JgGSblMaSCaM+SCwlYuxU6f/Ylhs2FxGL4gQIXX4dSmQ== From: Luca Ceresoli Subject: [PATCH 0/3] drm/bridge: get/put the bridge returned by drm_bridge_get_prev_bridge() Date: Wed, 09 Jul 2025 17:59:36 +0200 Message-Id: <20250709-drm-bridge-alloc-getput-drm_bridge_get_prev_bridge-v1-0-34ba6f395aaa@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-B4-Tracking: v=1; b=H4sIAOiRbmgC/y2NWQqDQBAFryL9nYZRI0avEmSYpTUNbsyoCOLd0 5p8Vj2od0CkwBShTg4ItHHkaRRIHwm4jxk7QvbCkKmsUKWq0IcBbWAvi+n7yWFHy7wul9c/r8X oWWJ/xupZKu/MK7U2BwnL1vJ+n76b8/wCDLWiIIQAAAA= X-Change-ID: 20250709-drm-bridge-alloc-getput-drm_bridge_get_prev_bridge-9470dca81bb3 To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Simona Vetter Cc: Hui Pu , Thomas Petazzoni , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Luca Ceresoli X-Mailer: b4 0.14.2 X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdefgdefjeelkecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffufffkgggtgffvvefosehtkeertdertdejnecuhfhrohhmpefnuhgtrgcuvegvrhgvshholhhiuceolhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepjeejhffgffelveehhfefudehtdeftdettdekgfekueeihedtieefudevjeffveegnecuffhomhgrihhnpehfrhgvvgguvghskhhtohhprdhorhhgpdhkvghrnhgvlhdrohhrghenucfkphepkeejrdduvddtrddvudekrddvtdejnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepkeejrdduvddtrddvudekrddvtdejpdhhvghloheplgduledvrdduieekrddurddufegnpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepudeipdhrtghpthhtohepjhhonhgrsheskhifihgsohhordhsvgdprhgtphhtthhopefnrghurhgvnhhtrdhpihhntghhrghrthesihguvggrshhonhgsohgrrhgurdgtohhmpdhrtghpthhtohepughrihdquggvvhgvlheslhhishhtshdrfhhrvggvuggvshhkthhophdrohhrghdprhgtphhtthhop ehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmpdhrtghpthhtohepthiiihhmmhgvrhhmrghnnhesshhushgvrdguvgdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehmrhhiphgrrhgusehkvghrnhgvlhdrohhrghdprhgtphhtthhopehthhhomhgrshdrphgvthgriiiiohhnihessghoohhtlhhinhdrtghomh X-GND-Sasl: luca.ceresoli@bootlin.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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This series adds drm_bridge_get/put() calls for DRM bridges returned by drm_bridge_get_prev_bridge(). This is part of the work towards removal of bridges from a still existing DRM pipeline without use-after-free. The grand plan was discussed in [1]. Here's the work breakdown (➜ marks the current series): 1. ➜ add refcounting to DRM bridges (struct drm_bridge) (based on devm_drm_bridge_alloc() [0]) A. ✔ add new alloc API and refcounting (in v6.16-rc1) B. ✔ convert all bridge drivers to new API (now in drm-misc-next) C. ✔ kunit tests (now in drm-misc-next) D. ✔ add get/put to drm_bridge_add/remove() + attach/detach() and warn on old allocation pattern (now in drm-misc-next) E. ➜ add get/put on drm_bridge accessors 1. … drm_bridge_chain_get_first_bridge() + add a cleanup action 2. drm_bridge_chain_get_last_bridge() 3. ➜ drm_bridge_get_prev_bridge() 4. drm_bridge_get_next_bridge() 5. drm_for_each_bridge_in_chain() 6. drm_bridge_connector_init 7. of_drm_find_bridge 8. drm_of_find_panel_or_bridge, *_of_get_bridge F. debugfs improvements 2. handle gracefully atomic updates during bridge removal 3. … avoid DSI host drivers to have dangling pointers to DSI devices 4. finish the hotplug bridge work, removing the "always-disconnected" connector, moving code to the core and potentially removing the hotplug-bridge itself (this needs to be clarified as points 1-3 are developed) [0] https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/0cc6aadd7fc1e629b715ea3d1ba537ef2da95eec [1] https://lore.kernel.org/lkml/20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com/t/#u Signed-off-by: Luca Ceresoli --- Luca Ceresoli (3): drm/bridge: get the bridge returned by drm_bridge_get_prev_bridge() drm/bridge: select_bus_fmt_recursive(): put the bridge obtained by drm_bridge_get_prev_bridge() drm/bridge: display-connector: put the bridge obtained by drm_bridge_get_prev_bridge() drivers/gpu/drm/bridge/display-connector.c | 4 ++-- drivers/gpu/drm/drm_bridge.c | 4 ++-- include/drm/drm_bridge.h | 9 ++++++++- 3 files changed, 12 insertions(+), 5 deletions(-) --- base-commit: 0f168e7be696a17487e83d1d47e5a408a181080f change-id: 20250709-drm-bridge-alloc-getput-drm_bridge_get_prev_bridge-9470dca81bb3 Best regards, -- Luca Ceresoli