From patchwork Fri Mar 14 10:31:17 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 14016632 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 5A6EBC282EC for ; Fri, 14 Mar 2025 10:40:21 +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:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; 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t=1741948304; 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: in-reply-to:in-reply-to:references:references; bh=IchMW5cPaVGupciOSvL/QWeDOAs3j9uz2T3WU11vBas=; b=FwWfXmphH0YQs4relpX07icAwCxBCsSkr6f43qURPHZIlDnKITvWbre+Gy+YLr85PUIPcG KFp3mgFlH8Z63SKX6ouW2Xm9icJIiCAR/be42+KfDmDyPVhP7zsiZ+nb09A11S76FcQFGZ TjBOn63k2hZ0aVmmu/h7UQ99fRUjVRX2deQoq3bQeqlzUykA9gd97bJwjbjaEM1S51bzOS fAp9qxgJzqKsxa9gfRV4wZYWKW+4drG4QB7DAtipW+LUz/gxAUIGgoZrh6XWEnJvMTsqV2 L0/Bdicz/XyHDrYmgU8dcylxVTxWs4BUcVQnWWtlZD+kU0lHCCNx4tG9fEA6/Q== From: Luca Ceresoli Date: Fri, 14 Mar 2025 11:31:17 +0100 Subject: [PATCH v7 04/11] drm/bridge: get/put the bridge reference in drm_bridge_attach/detach() MIME-Version: 1.0 Message-Id: <20250314-drm-bridge-refcount-v7-4-152571f8c694@bootlin.com> References: <20250314-drm-bridge-refcount-v7-0-152571f8c694@bootlin.com> In-Reply-To: <20250314-drm-bridge-refcount-v7-0-152571f8c694@bootlin.com> To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Marek Vasut , Stefan Agner , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Inki Dae , Jagan Teki , Marek Szyprowski Cc: Thomas Petazzoni , Anusha Srivatsa , Paul Kocialkowski , Dmitry Baryshkov , =?utf-8?q?Herv=C3=A9_Codina?= , Hui Pu , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Luca Ceresoli X-Mailer: b4 0.14.2 X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddufedtiedtucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredtjeenucfhrhhomhepnfhutggrucevvghrvghsohhlihcuoehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeiieeuvdfftefgueduleehueetgffgjeeitedtteetkeeuueeuueekveevvdeuveenucfkphepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegrtddtvdemudgsrgejmeegkehfjeemudeltgehnecuvehluhhsthgvrhfuihiivgepudenucfrrghrrghmpehinhgvthepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegrtddtvdemudgsrgejmeegkehfjeemudeltgehpdhhvghloheplgduledvrdduieekrddujeekrdduudekngdpmhgrihhlfhhrohhmpehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopeefuddprhgtphhtthhopefjuhhirdfruhesghgvhhgvrghlthhhtggrrhgvrdgtohhmpdhrtghpthhtohepihhnkhhirdgurggvsehsrghmshhunhhgrdgtohhmpdhrtghpthhtohepmhgrrhgvgiesuggvnhigrdguvgdprhgtphhtthhopehjvghrn hgvjhdrshhkrhgrsggvtgesghhmrghilhdrtghomhdprhgtphhtthhopehprghulhhksehshihsqdgsrghsvgdrihhopdhrtghpthhtoheprghsrhhivhgrthhssehrvgguhhgrthdrtghomhdprhgtphhtthhopehmrhhiphgrrhgusehkvghrnhgvlhdrohhrghdprhgtphhtthhopehjohhnrghssehkfihisghoohdrshgv X-GND-Sasl: luca.ceresoli@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250314_033145_982558_B01F1EAE X-CRM114-Status: GOOD ( 10.99 ) 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 drm_bridge_attach() adds the bridge to the encoder chain, so take a reference for that. Vice versa in drm_bridge_detach(). Signed-off-by: Luca Ceresoli Reviewed-by: Maxime Ripard --- Changes in v7: - in v6 this was part of "drm/bridge: add support for refcounted DRM bridges", now split to a separate patch --- drivers/gpu/drm/drm_bridge.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 72fa51d4dd2337f97c2bd65cfabf9cee05b661b4..da85694e9310f1f910bc8a5aa5d95a91d9254888 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -370,11 +370,17 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, if (!encoder || !bridge) return -EINVAL; - if (previous && (!previous->dev || previous->encoder != encoder)) - return -EINVAL; + drm_bridge_get(bridge); - if (bridge->dev) - return -EBUSY; + if (previous && (!previous->dev || previous->encoder != encoder)) { + ret = -EINVAL; + goto err_put_bridge; + } + + if (bridge->dev) { + ret = -EBUSY; + goto err_put_bridge; + } bridge->dev = encoder->dev; bridge->encoder = encoder; @@ -423,6 +429,8 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, "failed to attach bridge %pOF to encoder %s\n", bridge->of_node, encoder->name); +err_put_bridge: + drm_bridge_put(bridge); return ret; } EXPORT_SYMBOL(drm_bridge_attach); @@ -443,6 +451,7 @@ void drm_bridge_detach(struct drm_bridge *bridge) list_del(&bridge->chain_node); bridge->dev = NULL; + drm_bridge_put(bridge); } /**