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 6FF36CD3430 for ; Mon, 4 May 2026 10:45:41 +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=LNXHjKbecVLNXCi3F/uO2gZdoR1K6SlYY6/tc07aOsM=; b=F5BIEpyFt7Ue6t os+9/RAdJykaYklDWalEsLuICup4baTyEGlG+RQDie8Axk6HRSUoY7ENiV29UBQitrfJgVr1FPQDd Ztb9LCHe4m9mZdTkXvKogbzDua2KWCj4k34BCuGgM4y9edBwzq5rBcFXcbPdc5+13hYTwDOujzXfb 0GhAyrsAKFS3kX1PA13kmUMYZxsl+s728PiZKV9kqiO2pNb90St8tJtUXuCP5iigIxQruW98xyI8s XajwUkneH0eKdK+mydVF7moggv6IUDC6v6VPBFwsE1Pow8vZze8cis97kt4C692YqroTH7wcKDogi WFwRKe47MYwpjhXjGTYg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wJqnm-0000000CxXy-2tqC; Mon, 04 May 2026 10:45:26 +0000 Received: from smtpout-03.galae.net ([185.246.85.4]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wJqni-0000000CxXC-0GSh for linux-arm-kernel@lists.infradead.org; Mon, 04 May 2026 10:45:24 +0000 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 73A9B4E42BBC; Mon, 4 May 2026 10:45:19 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 44F0A5FD5F; Mon, 4 May 2026 10:45:19 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id D2C1311AD268A; Mon, 4 May 2026 12:45:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1777891517; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding; bh=LNXHjKbecVLNXCi3F/uO2gZdoR1K6SlYY6/tc07aOsM=; b=bxhnLLfVcGCWieMIIvjOltGpSz6JLPeiyNW5HL/z6dqyAqauN398d067tzUUnzwc8kAwuE 3C2SAv1LuEnvLi0znC2jSsUhqKHwjBwSSf/QxSdfyjXQheojH2b5EWQR5sED8OmyB2JHc2 cydVE26es5udZguSEi8sXhQ3VR1Wkdfo6/ohfQyPQUbzB+lLnwJuEqW3IVTeoBiuxGRxn1 bW7J55ns1gjPWG7+Kw+YC0EBa+voKNWlIGls6+3RjXM/tBE2SO9lMl68JJ637m+/lNND2T Pi2dveE8PZAPlL95WSdz1DDcsiXJKnaDP3iFObGBOlAeU/OSB2WU2cnZOUAvmg== From: Luca Ceresoli Subject: [PATCH v4 00/11] drm/bridge: handle refcounting for bridge-only callers of drm_of_find_panel_or_bridge() Date: Mon, 04 May 2026 12:45:03 +0200 Message-Id: <20260504-drm-bridge-alloc-getput-panel_or_bridge-v4-0-b578c3daaf10@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-B4-Tracking: v=1; b=H4sIAK94+GkC/52Oy4oCMRREf0WynkhebZxZzX+IyE1y1UjbaZLYK NL/buIDFDfisqjinDqThNFjIn+TM4k4+ORDV4L6mRC7hW6D1LuSiWBixhRn1MU9NdG70kDbBks 3mPtDpj102K5CXN1LJRrGjZwjgCOF1kdc++PVtFjecjqYHdpc8XWx9SmHeLpeGXjdPazyY+vAK aNgHePW6V/g638TQm59N7VhT6p3EE9kMf+cLApZSca0UsCt0u9k+SVZ1s+N1KZpZhqceyWP43g B+66Nn6YBAAA= 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 , Sumit Semwal , 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 , Biju Das 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-20260504_034522_394317_B34C6D15 X-CRM114-Status: GOOD ( 13.23 ) 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. All patches acked/reviewed except patches 3, 4 and 10. == 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 (v7.2) 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 v4: - Fixed patches 3 and 10 - Minor fixes to patches 1 and 2 - Removed bouncing addresses yongqin.liu@linaro.org and xinliang.liu@linaro.org from Cc - Link to v3: https://patch.msgid.link/20260428-drm-bridge-alloc-getput-panel_or_bridge-v3-0-a537b5567add@bootlin.com 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 | 49 +++++++++++++++++++++++++--- drivers/gpu/drm/drm_of.c | 26 +++++++-------- drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c | 9 +++-- drivers/gpu/drm/msm/hdmi/hdmi.c | 14 ++++++-- drivers/gpu/drm/xlnx/zynqmp_dp.c | 19 ++++++----- include/drm/drm_bridge.h | 7 ++++ 12 files changed, 128 insertions(+), 68 deletions(-) --- base-commit: 5919a056c7426ba74d0199252c7304566dadf161 change-id: 20260410-drm-bridge-alloc-getput-panel_or_bridge-42501b38eaad Best regards, -- Luca Ceresoli