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 0E15DFF885A for ; Tue, 28 Apr 2026 15:31:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To: Content-Transfer-Encoding:Content-Type:MIME-Version:Message-Id:Date:Subject: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=OEF9VP5XUoD9pYJWbQoWCnjrQfSnlUkjr7ryReb47jg=; b=t9BIAn0gr7x6HP D/pLE1xKCsAxgV6s89Zy2/82LP/Ma75Z2rrB5/B2WSVsjnq1/7LTf2IzBQn90+FSj7mwma1jnBKcT hognbN9ukIe9CVhqHf4/Tpg50tTCSVYNFUBTSeA1ayAcJ8mzRqK4BKYE/256jtKpWLANtUtPqxA8m DZx2w0etlj7AOf8PIj+E9OVMDJa79G+BfpqYKZOz50F9g8ivjUSKNhvdzlmHapuo4aZU/CtzuXO0Y 3t6Um5A7QaUJSI2wiwLdig9I3KFknZG61Yequ9ED2Ft5/WJRRaUE9cZa9XuBsWysZDTjENEvkdcRj 3YQjx6987lmyhes6MIow==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHkPI-00000001jsi-0HNC; Tue, 28 Apr 2026 15:31:28 +0000 Received: from smtpout-04.galae.net ([185.171.202.116]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHkPF-00000001js8-1aYI for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2026 15:31:27 +0000 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id AD8C1C5EF12; Tue, 28 Apr 2026 15:32:05 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id E8B40601D0; Tue, 28 Apr 2026 15:31:21 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 6752F1072861C; Tue, 28 Apr 2026 17:31:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1777390280; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding; bh=OEF9VP5XUoD9pYJWbQoWCnjrQfSnlUkjr7ryReb47jg=; b=AOKI61nma48mkjqVr9Gb0ISnASEq8351KRUjUxWqAmufoigi8v8gQNPeUG8f6NrpREttuy FDlGkif5jmdraMwjeo5PB+wBrSrAsmy8r4Fc9tWTM/AiNLU6EpcWu7WyryalA9oIWDWt5j QqQwYL9Vd0e63jTQDaButn0NS4xNLxk4OAfhfrewW7IeETq9w78lYqk06W2flRsFU7Lfn3 gGTpOiupKUomuK8ijPXEo+RXSSJkdrTK8EF7Onj0e9xr9PohJjrsv8fLuuaeeAVzVDr7p5 pVIgV1WqujC0gJ9/mpnZ6BAXCGwFdRyXvciqoaJN+ajkcii4HobOrQqxrwdzjQ== From: Luca Ceresoli Subject: [PATCH v3 00/11] drm/bridge: handle refcounting for bridge-only callers of drm_of_find_panel_or_bridge() Date: Tue, 28 Apr 2026 17:30:49 +0200 Message-Id: <20260428-drm-bridge-alloc-getput-panel_or_bridge-v3-0-a537b5567add@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-B4-Tracking: v=1; b=H4sIAKnS8GkC/42O0Q6CIBiFX8VxHQ2Q0rrqPVpzCL9KU3CAruZ89 9Bqqzsvz87Z950JeXAaPDonE3Iwaq+tiSHdJUg2wtSAtYoZMcKOhFOCletw6bSKjWhbK3ENoR8 C7oWBtrCu+JScHQgt0xyEUCjSegeVfqym6+2d/VDeQYYFvywa7YN1z/XKSJfd15puto4UEyykI lSq7CRodSmtDa02e2k7tHhH9kNm+XYyi2SeEpJxLqjk2T95nucX8lgv3EwBAAA= X-Change-ID: 20260410-drm-bridge-alloc-getput-panel_or_bridge-42501b38eaad To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Clark , Dmitry Baryshkov , Abhinav Kumar , Jessica Zhang , Sean Paul , Marijn Suijten , Xinliang Liu , Sumit Semwal , Yongqin Liu , John Stultz , Tomi Valkeinen , Michal Simek Cc: Hui Pu , Ian Ray , Thomas Petazzoni , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, Luca Ceresoli , Laurent Pinchart , Dmitry Baryshkov X-Mailer: b4 0.15.2 X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260428_083125_565655_30C3EDBD X-CRM114-Status: GOOD ( 12.71 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This series converts all the bridge-only callers of the deprecated drm_of_find_panel_or_bridge() API to a new, simpler API that handles bridge refcounting. == Series description * Patch 1 (new in v2) makes drm_bridge_get/put() ignore ERR_PTR pointers, not only NULL pointers * Patch 2 introduces of_drm_get_bridge_by_endpoint() as a replacement for bridge-only calls to drm_of_find_panel_or_bridge(); the new function refcounts the bridge and is simpler * The following patches convert all bridge-only users to the new API * The last patch forbids new bridge-only calls to drm_of_find_panel_or_bridge() == Grand plan This is part of the work to support hotplug of DRM bridges. The grand plan was discussed in [0]. Here's the work breakdown (➜ marks the current series): 1. ➜ add refcounting to DRM bridges struct drm_bridge, based on devm_drm_bridge_alloc() A. ✔ add new alloc API and refcounting (v6.16) B. ✔ convert all bridge drivers to new API (v6.17) C. ✔ kunit tests (v6.17) D. ✔ add get/put to drm_bridge_add/remove() + attach/detach() and warn on old allocation pattern (v6.17) E. ➜ add get/put on drm_bridge accessors 1. ✔ drm_bridge_chain_get_first_bridge(), add cleanup action (v6.18) 2. ✔ drm_bridge_get_prev_bridge() (v6.18) 3. ✔ drm_bridge_get_next_bridge() (v6.19) 4. ✔ drm_for_each_bridge_in_chain() (v6.19) 5. ✔ drm_bridge_connector_init (v6.19) 6. ✔ protect encoder bridge chain with a mutex (v7.2) 7. ➜ of_drm_find_bridge a. ✔ add of_drm_get_bridge() (v7.0), convert basic direct users (v7.0-v7.1) b. ✔ convert direct of_drm_get_bridge() users, part 2 (v7.0) c. ✔ convert direct of_drm_get_bridge() users, part 3 (v7.0) d. ✔ convert direct of_drm_get_bridge() users, part 4 (v7.1-v7.2) e. ➜ convert bridge-only drm_of_find_panel_or_bridge() users 8. drm_of_find_panel_or_bridge, *_of_get_bridge 9. ✔ enforce drm_bridge_add before drm_bridge_attach (v6.19) F. ✔ debugfs improvements 1. ✔ add top-level 'bridges' file (v6.16) 2. ✔ show refcount and list lingering bridges (v6.19) 2. … handle gracefully atomic updates during bridge removal A. ✔ Add drm_bridge_enter/exit() to protect device resources (v7.0) B. … protect private_obj removal from list C. ✔ Add drm_bridge_clear_and_put() (v7.1) 3. … DSI host-device driver interaction 4. ✔ removing the need for the "always-disconnected" connector 5. ✔ Migrate i.MX LCDIF driver to bridge-connector (v7.2) 6. … DRM bridge hotplug A. … Bridge hotplug management in the DRM core 1. … bridge-connector: attach encoder to the connector B. Device tree description [0] https://lore.kernel.org/lkml/20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com/#t Signed-off-by: Luca Ceresoli --- Changes in v3: - patch 3, 8, 10: fixed ERR_PTR deref in the -ENODEV case, and removed Dmitry's R-by from those patches as they are changed - Added review trailers to the other patches - Link to v2: https://patch.msgid.link/20260428-drm-bridge-alloc-getput-panel_or_bridge-v2-0-4300744a1c47@bootlin.com Changes in v2: - Added patch to ignore ERR_PTR values in drm_bridge_get/put() - Changed API to return the bridge (or a ERR_PTR) in the return value, not as a double-pointer output parameter - Adapted all patches to the new API, dropped Dmitry's review tags as the patches are all modified - Removed bouncing addresses from Cc list - Link to v1: https://patch.msgid.link/20260413-drm-bridge-alloc-getput-panel_or_bridge-v1-0-acd01cd79a1f@bootlin.com --- Luca Ceresoli (11): drm/bridge: drm_bridge_get/put(): ignore ERR_PTR drm/bridge: add of_drm_get_bridge_by_endpoint() drm/msm/hdmi: switch to of_drm_get_bridge_by_endpoint() drm/hisilicon/kirin: switch to of_drm_get_bridge_by_endpoint() drm/bridge: chrontel-ch7033: switch to of_drm_get_bridge_by_endpoint() drm/bridge: lontium-lt9611uxc: switch to of_drm_get_bridge_by_endpoint() drm/bridge: lt9611: switch to of_drm_get_bridge_by_endpoint() drm/bridge: adv7511: switch to of_drm_get_bridge_by_endpoint() drm/bridge: lt8713sx: switch to of_drm_get_bridge_by_endpoint() drm: zynqmp_dp: switch to of_drm_get_bridge_by_endpoint() drm: of: forbid bridge-only calls to drm_of_find_panel_or_bridge() drivers/gpu/drm/bridge/adv7511/adv7511.h | 1 - drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 15 ++++---- drivers/gpu/drm/bridge/chrontel-ch7033.c | 28 +++++++-------- drivers/gpu/drm/bridge/lontium-lt8713sx.c | 10 +++--- drivers/gpu/drm/bridge/lontium-lt9611.c | 9 +++-- drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 9 +++-- drivers/gpu/drm/drm_bridge.c | 53 ++++++++++++++++++++++++---- drivers/gpu/drm/drm_of.c | 26 +++++++------- drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c | 9 +++-- drivers/gpu/drm/msm/hdmi/hdmi.c | 11 ++++-- drivers/gpu/drm/xlnx/zynqmp_dp.c | 19 +++++----- include/drm/drm_bridge.h | 8 +++++ 12 files changed, 128 insertions(+), 70 deletions(-) --- base-commit: 6dbe0c5375e4f88c8d7c90790e0ea29d565b5d0a change-id: 20260410-drm-bridge-alloc-getput-panel_or_bridge-42501b38eaad Best regards, -- Luca Ceresoli