From nobody Tue Dec 16 14:22:04 2025 Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) (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 EDDB01A8403; Thu, 6 Feb 2025 18:15:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.198 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738865712; cv=none; b=aucE6wI7mnKWDfmlS0zG0V9zXHzagdunC/BQEJSBOQ6YRRP/vSg3oR4MfRNwCAhJfle9y3Ig2X95NfBuFXPAH36wwq/EY2qIJBRNu7zS/rO+VOQhirdUAMWhd3OxBzQ6dCWhL8/Z7cTV/IsAsCNMPv5MqnGWs8hhBJhNB267Xcg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738865712; c=relaxed/simple; bh=hUK7EUCd5pSJ3phtZiunKrXblXUguWhVr8p9Vm2X8Ts=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=HIwM+scm1Ekvm+oH1pst3KWqn2nD+r0stYf1GizlQdTr7jaczLNLHjZTPrY2uB56k8YFNWiXvBjbFQfvDYysmzKvse5a/2syyjJQ1bRp2NKqHF5D/UUzX5ZnWQGyvvPHO/8ahQg3RlnzIRDLHI7eaUAXN9xHDkY2edwRfrmdz+A= ARC-Authentication-Results: i=1; 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bh=8iJmfJohMLskNWh1/d0vxg24JxdxKf1x+OOa7rjoPoQ=; b=lBoVSeHlKoZKgObkr/7yH+eB6a28/qBL2c815XIuOrLvGMzwIO27CvahjbLLJROTvzCE5L 3YotwQGDyNa6viU6GczZ7FATkIvf6fxX4rgB7bhbgZ8cHCmB3uCGKyLRPxFjHQ47iqZG1I 94jMS/fhat15/+DcEg8+cFPfIR7V8/Pn9qJXL2Ry9LWrsDHyb+kZ1nYyOgWAz468z3mAh7 IPmWTzzP2wZVS/bJpqm7lgpZRA8eTtMJ5iPH3dfwvphiPTbt7y9pNdG3ZcVnlC3XtwybOh UkkZX6nQW/s8PqE2cmf9S9xN42UgSc01janAnUjiCVEiOSz5fxKe92B+Ql/XVg== From: Luca Ceresoli Date: Thu, 06 Feb 2025 19:14:27 +0100 Subject: [PATCH v6 12/26] drm/bridge: allow bridges to be informed about added and removed bridges 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: <20250206-hotplug-drm-bridge-v6-12-9d6f2c9c3058@bootlin.com> References: <20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com> In-Reply-To: <20250206-hotplug-drm-bridge-v6-0-9d6f2c9c3058@bootlin.com> To: Simona Vetter , Inki Dae , Jagan Teki , Marek Szyprowski , Catalin Marinas , Will Deacon , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Daniel Thompson , Andrzej Hajda , Jonathan Corbet , Sam Ravnborg , Boris Brezillon , Nicolas Ferre , Alexandre Belloni , Claudiu Beznea , Jessica Zhang Cc: Paul Kocialkowski , Maxime Ripard , Dmitry Baryshkov , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Thomas Zimmermann , David Airlie , =?utf-8?q?Herv=C3=A9_Codina?= , Thomas Petazzoni , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Paul Kocialkowski , Luca Ceresoli X-Mailer: b4 0.14.2 X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddvjedtkecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephfffufggtgfgkfhfjgfvvefosehtjeertdertdejnecuhfhrohhmpefnuhgtrgcuvegvrhgvshholhhiuceolhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepieeiuedvffetgfeuudelheeutefggfejieettdetteekueeuueeukeevvedvueevnecukfhppedvrgdtvdemieejtdemvddtvddtmegvrgdtudemhegrgedtmedvughfieemrgdulegvmedutgejgeenucevlhhushhtvghrufhiiigvpeelnecurfgrrhgrmhepihhnvghtpedvrgdtvdemieejtdemvddtvddtmegvrgdtudemhegrgedtmedvughfieemrgdulegvmedutgejgedphhgvlhhopegluddvjedrtddruddrudgnpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepfeekpdhrtghpthhtoheptggrthgrlhhinhdrmhgrrhhinhgrshesrghrmhdrtghomhdprhgtphhtthhopehsrdhhrghuvghrsehpvghnghhuthhrohhnihigrdguvgdprhgtphhtthhopegrlhgvgigrnhgurhgvrdgsvghllhhonhhisegsohhothhlihhnrdgtohhmp dhrtghpthhtoheptghlrghuughiuhdrsggviihnvggrsehtuhigohhnrdguvghvpdhrtghpthhtohepmhdrshiihihprhhofihskhhisehsrghmshhunhhgrdgtohhmpdhrtghpthhtoheptghorhgsvghtsehlfihnrdhnvghtpdhrtghpthhtohepshhimhhonhgrsehffhiflhhlrdgthhdprhgtphhtthhopegurhhiqdguvghvvghlsehlihhsthhsrdhfrhgvvgguvghskhhtohhprdhorhhg X-GND-Sasl: luca.ceresoli@bootlin.com In preparation for allowing bridges to be added to and removed from a DRM card without destroying the whole card, add a new DRM bridge function called on addition and removal of bridges. Signed-off-by: Luca Ceresoli --- Changed in v6: - rebased fixing conflicts Changed in v5: - fixed kerneldoc errors This patch was added in v4. --- drivers/gpu/drm/drm_bridge.c | 12 ++++++++++++ include/drm/drm_bridge.h | 23 +++++++++++++++++++++++ 2 files changed, 35 insertions(+) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index b0834b8644284e5f7751cec81724af849b4180e7..1955a231378050abf1071d74a14= 5831b425c47c5 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -207,12 +207,18 @@ LIST_HEAD(bridge_list); */ void drm_bridge_add(struct drm_bridge *bridge) { + struct drm_bridge *br, *tmp; + mutex_init(&bridge->hpd_mutex); =20 if (bridge->ops & DRM_BRIDGE_OP_HDMI) bridge->ycbcr_420_allowed =3D !!(bridge->supported_formats & BIT(HDMI_COLORSPACE_YUV420)); =20 + list_for_each_entry_safe(br, tmp, &bridge_list, list) + if (br->funcs->bridge_event_notify) + br->funcs->bridge_event_notify(br, DRM_EVENT_BRIDGE_ADD, bridge); + mutex_lock(&bridge_lock); list_add_tail(&bridge->list, &bridge_list); mutex_unlock(&bridge_lock); @@ -249,10 +255,16 @@ EXPORT_SYMBOL(devm_drm_bridge_add); */ void drm_bridge_remove(struct drm_bridge *bridge) { + struct drm_bridge *br, *tmp; + mutex_lock(&bridge_lock); list_del_init(&bridge->list); mutex_unlock(&bridge_lock); =20 + list_for_each_entry_safe(br, tmp, &bridge_list, list) + if (br->funcs->bridge_event_notify) + br->funcs->bridge_event_notify(br, DRM_EVENT_BRIDGE_REMOVE, bridge); + mutex_destroy(&bridge->hpd_mutex); } EXPORT_SYMBOL(drm_bridge_remove); diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index 1561347c4991dac6022319774510f9560c9283c3..ad7ba444a13e5ecf16f996de374= 2e4ac67dc21f1 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -56,6 +56,11 @@ enum drm_bridge_attach_flags { DRM_BRIDGE_ATTACH_NO_CONNECTOR =3D BIT(0), }; =20 +enum drm_bridge_event_type { + DRM_EVENT_BRIDGE_ADD, + DRM_EVENT_BRIDGE_REMOVE, +}; + /** * struct drm_bridge_funcs - drm_bridge control functions */ @@ -729,6 +734,24 @@ struct drm_bridge_funcs { struct drm_bridge *bridge, bool enable, int direction); =20 + /** + * @bridge_event_notify: + * + * Notify that another bridge is being added or removed. + * + * This callback is optional. Bridges implementing it must always + * check whether the event refers to a bridge they actually need to + * interact with. + * + * @bridge: bridge being notified + * @event: event happened (add/remove bridge) + * @event_bridge: the bridge mentioned by the event (i.e. the + * bridge being added or removed) + */ + void (*bridge_event_notify)(struct drm_bridge *bridge, + enum drm_bridge_event_type event, + struct drm_bridge *event_bridge); + /** * @debugfs_init: * --=20 2.34.1