From patchwork Wed Mar 26 17:47:35 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 14030429 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 C23B5C36008 for ; Wed, 26 Mar 2025 17:51:49 +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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s=gm1; t=1743011278; 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=ndazw8iVlLF3DncKQTioWTpLoiIsd0ajB8SBQX3Fyiw=; b=ljjzP9gJSK1/q889Om1tXDUFjofNvYanCtJ8+RIc57y3y4lkdYcmLu82vzV1ie0TG/2P2K Yy4Qu4W/uypQTrkaOzbHzys2H/py6bsfa5zHWj8D7qdm1x63D1O+PpiXFDeTpWzru0otb7 t5WKpTsFAQtBVNauH2txaBUX5nxmuczqzjXfFvi2Ghvm1iUK1yIlvhEulbUhhiUc+EGbL5 NG39xUB6rXF5nn9vh4671++i8uXHtdz/I9xVII8wQ9g3yVISwHbeLaAawZ1X9gLHDvMo6N G9WHrInmiyIxt/bTth5T+CdhLCSnJ1AMhWWPlwmc7v+OGi/murpMKUO3RTC8Kw== From: Luca Ceresoli Date: Wed, 26 Mar 2025 18:47:35 +0100 Subject: [PATCH v9 1/5] drm/bridge: add devm_drm_bridge_alloc() MIME-Version: 1.0 Message-Id: <20250326-drm-bridge-refcount-v9-1-5e0661fe1f84@bootlin.com> References: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@bootlin.com> In-Reply-To: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@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: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdduieeiudejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredtjeenucfhrhhomhepnfhutggrucevvghrvghsohhlihcuoehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeiieeuvdfftefgueduleehueetgffgjeeitedtteetkeeuueeuueekveevvdeuveenucfkphepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvpdhhvghloheplgduledvrdduieekrddujeekrdejhegnpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepfedupdhrtghpthhtohepmhgrrghrthgvnhdrlhgrnhhkhhhorhhstheslhhinhhugidrihhnthgvlhdrtghomhdprhgtphhtthhopehmrghrvgigseguvghngidruggvpdhrtghpthhtohepihhmgieslhhishhtshdrlhhinhhugidruggvvhdprhgtphhtt hhopefjuhhirdfruhesghgvhhgvrghlthhhtggrrhgvrdgtohhmpdhrtghpthhtohepshhimhhonhgrsehffhiflhhlrdgthhdprhgtphhtthhopehnvghilhdrrghrmhhsthhrohhngheslhhinhgrrhhordhorhhgpdhrtghpthhtoheprghirhhlihgvugesghhmrghilhdrtghomhdprhgtphhtthhopehhvghrvhgvrdgtohguihhnrgessghoohhtlhhinhdrtghomh X-GND-Sasl: luca.ceresoli@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250326_104801_840059_1526C7D9 X-CRM114-Status: GOOD ( 14.49 ) 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 Add a macro to allocate and initialize a DRM bridge embedded within a private driver struct. Compared to current practice, which is based on [devm_]kzalloc() allocation followed by open-coded initialization of fields, this allows to have a common and explicit API to allocate and initialize DRM bridges. Besides being useful to consolidate bridge driver code, this is a fundamental step in preparation for adding dynamic lifetime to bridges based on refcount. Reviewed-by: Maxime Ripard Signed-off-by: Luca Ceresoli --- Changes in v9: none Changes in v8: none 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 | 22 ++++++++++++++++++++++ include/drm/drm_bridge.h | 17 +++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index ef98e21dc593f38a2d3c67b850032ece38bec5e8..84fa1a1330cbabd309526829fff70971cfed1dcd 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -199,6 +199,28 @@ static DEFINE_MUTEX(bridge_lock); static LIST_HEAD(bridge_list); +void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, + const struct drm_bridge_funcs *funcs) +{ + void *container; + struct drm_bridge *bridge; + + if (!funcs) { + dev_warn(dev, "Missing funcs pointer\n"); + return ERR_PTR(-EINVAL); + } + + container = devm_kzalloc(dev, size, GFP_KERNEL); + if (!container) + return ERR_PTR(-ENOMEM); + + bridge = container + offset; + bridge->funcs = funcs; + + return container; +} +EXPORT_SYMBOL(__devm_drm_bridge_alloc); + /** * drm_bridge_add - add the given bridge to the global bridge list * diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index cdad3b78a195aa39776c93e2371217d3d3fb6064..a59277674d5a2937e324d3ce48f934418788053f 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -941,6 +941,23 @@ drm_priv_to_bridge(struct drm_private_obj *priv) return container_of(priv, struct drm_bridge, base); } +void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, + const struct drm_bridge_funcs *funcs); + +/** + * devm_drm_bridge_alloc - Allocate and initialize a bridge + * @dev: struct device of the bridge device + * @type: the type of the struct which contains struct &drm_bridge + * @member: the name of the &drm_bridge within @type + * @funcs: callbacks for this bridge + * + * Returns: + * Pointer to new bridge, or ERR_PTR on failure. + */ +#define devm_drm_bridge_alloc(dev, type, member, funcs) \ + ((type *)__devm_drm_bridge_alloc(dev, sizeof(type), \ + offsetof(type, member), funcs)) + void drm_bridge_add(struct drm_bridge *bridge); int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge); void drm_bridge_remove(struct drm_bridge *bridge); From patchwork Wed Mar 26 17:47:36 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 14030430 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 38C9EC36008 for ; Wed, 26 Mar 2025 17:53:33 +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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s=gm1; t=1743011280; 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=zhjBmXsf/LmBdhRk5NLGeDB408E/96bpBJOsIdR68d4=; b=GPP567yfHMyK57Rh6puGQTwdX5hnay2mru9whH1UGqvFQSR3QbIoxeoQ9FSoqN1cTKchlE kczeAYMHtW/ZkCsYO+7afCk9BYhYYnm/4PZcFx7EoxPjCUJORAvAtwSh5XiKFGkz/LuINO 6YXAFHApPIj3r6vnrknaZkFeVUSmqsS6sVwEwfF0O+YMiRjwh3HZgYfi93FJvw7t9rjkzw HYi/xKcph7PP+YhHCYUZTCnOoaq702UMB3HlQ7TqMx7MZSiVfBpSUGu8QSFw0NgeutlKSL AYRp1kejqalRl+e+H2FBvpJqZo3CT03g76/Q2uEsy4xs2/qQg2a692g8dvU1qQ== From: Luca Ceresoli Date: Wed, 26 Mar 2025 18:47:36 +0100 Subject: [PATCH v9 2/5] drm/bridge: add support for refcounting MIME-Version: 1.0 Message-Id: <20250326-drm-bridge-refcount-v9-2-5e0661fe1f84@bootlin.com> References: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@bootlin.com> In-Reply-To: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@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: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdduieeiudejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredtjeenucfhrhhomhepnfhutggrucevvghrvghsohhlihcuoehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeehjefgudegvddukeegvedtgfduudehtdfgteefvefgheekjeehvdeihfdtfffhkeenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecukfhppedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgdphhgvlhhopegludelvddrudeikedrudejkedrjeehngdpmhgrihhlfhhrohhmpehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopeefuddprhgtphhtthhopehmrggrrhhtvghnrdhlrghnkhhhohhrshhtsehlihhnuhigrdhinhhtvghlrdgtohhmpdhrtghpthhtohepmhgrrhgvgiesuggvnhigrdguvgdprhgtphhtthhopehimhigsehli hhsthhsrdhlihhnuhigrdguvghvpdhrtghpthhtohepjfhuihdrrfhusehgvghhvggrlhhthhgtrghrvgdrtghomhdprhgtphhtthhopehsihhmohhnrgesfhhffihllhdrtghhpdhrtghpthhtohepnhgvihhlrdgrrhhmshhtrhhonhhgsehlihhnrghrohdrohhrghdprhgtphhtthhopegrihhrlhhivggusehgmhgrihhlrdgtohhmpdhrtghpthhtohephhgvrhhvvgdrtghoughinhgrsegsohhothhlihhnrdgtohhm X-GND-Sasl: luca.ceresoli@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250326_104802_431956_15C6B372 X-CRM114-Status: GOOD ( 24.38 ) 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 bridges are currently considered as a fixed element of a DRM card, and thus their lifetime is assumed to extend for as long as the card exists. New use cases, such as hot-pluggable hardware with video bridges, require DRM bridges to be added to and removed from a DRM card without tearing the card down. This is possible for connectors already (used by DP MST), it is now needed for DRM bridges as well. As a first preliminary step, make bridges reference-counted to allow a struct drm_bridge (along with the private driver structure embedding it) to stay allocated even after the driver has been removed, until the last reference is put. Signed-off-by: Luca Ceresoli Reviewed-by: Maxime Ripard --- Changes in v9: - make drm_bridge_put() void as discussed in https://lore.kernel.org/lkml/20250326102304.49510630@booty/ - slightly simplify code flow in drm_bridge_get/put() - removed Maxime's Reviewed-by due to the above changes Changes in v8: - move back drm_bridge_get/put() to the .c file, make __drm_bridge_free private - move back drm_bridge_put_void() to .c, not used in this series outside of drm_bridge.c - remove drm_bridge_put_and_clear(), not used in this series - minor docs and coding style tweaks Changes in v7: - export drm_bridge_put_void - struct drm_bridge: use container pointer instead of container_offset - remove drm_bridge_is_refcounted() - remove all DRM_DEBUG()s - drm_bridge_get/put: accept NULL pointer and return the bridge pointer to allow pass-through calls - extract to separate patches: - the addition of drm_bridge_alloc - the addition of drm_bridge_get/put() to drm_bridge_add/remove() - the addition of drm_bridge_get/put() to drm_bridge_attach/detach() - fix a typo, slightly improve kerneldoc Changes in v6: - use drm_warn, not WARN_ON (Jani Nikula) - Add devm_drm_bridge_alloc() to replace drm_bridge_init() (similar to drmm_encoder_alloc) - Remove .destroy func: deallocation is done via the struct offset computed by the devm_drm_bridge_alloc() macro - use fixed free callback, as the same callback is used in all cases anyway (remove free_cb, add bool is_refcounted) - add drm_bridge_get/put() to drm_bridge_attach/detach() (add the bridge to a list) - make some DRM_DEBUG() strings more informative This patch was added in v5. --- drivers/gpu/drm/drm_bridge.c | 63 +++++++++++++++++++++++++++++++++++++++++++- include/drm/drm_bridge.h | 19 +++++++++++++ 2 files changed, 81 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 84fa1a1330cbabd309526829fff70971cfed1dcd..22b459af112fd3cd2db00aa16668d270e028b307 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -199,23 +199,84 @@ static DEFINE_MUTEX(bridge_lock); static LIST_HEAD(bridge_list); +static void __drm_bridge_free(struct kref *kref) +{ + struct drm_bridge *bridge = container_of(kref, struct drm_bridge, refcount); + + kfree(bridge->container); +} + +/** + * drm_bridge_get - Acquire a bridge reference + * @bridge: DRM bridge + * + * This function increments the bridge's refcount. + * + * Returns: + * Pointer to @bridge. + */ +struct drm_bridge *drm_bridge_get(struct drm_bridge *bridge) +{ + if (bridge) + kref_get(&bridge->refcount); + + return bridge; +} +EXPORT_SYMBOL(drm_bridge_get); + +/** + * drm_bridge_put - Release a bridge reference + * @bridge: DRM bridge + * + * This function decrements the bridge's reference count and frees the + * object if the reference count drops to zero. + */ +void drm_bridge_put(struct drm_bridge *bridge) +{ + if (bridge) + kref_put(&bridge->refcount, __drm_bridge_free); +} +EXPORT_SYMBOL(drm_bridge_put); + +/** + * drm_bridge_put_void - wrapper to drm_bridge_put() taking a void pointer + * + * @data: pointer to @struct drm_bridge, cast to a void pointer + * + * Wrapper of drm_bridge_put() to be used when a function taking a void + * pointer is needed, for example as a devm action. + */ +static void drm_bridge_put_void(void *data) +{ + struct drm_bridge *bridge = (struct drm_bridge *)data; + + drm_bridge_put(bridge); +} + void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, const struct drm_bridge_funcs *funcs) { void *container; struct drm_bridge *bridge; + int err; if (!funcs) { dev_warn(dev, "Missing funcs pointer\n"); return ERR_PTR(-EINVAL); } - container = devm_kzalloc(dev, size, GFP_KERNEL); + container = kzalloc(size, GFP_KERNEL); if (!container) return ERR_PTR(-ENOMEM); bridge = container + offset; + bridge->container = container; bridge->funcs = funcs; + kref_init(&bridge->refcount); + + err = devm_add_action_or_reset(dev, drm_bridge_put_void, bridge); + if (err) + return ERR_PTR(err); return container; } diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index a59277674d5a2937e324d3ce48f934418788053f..df9bbf6fd1fb522add28b76406b74cdb7391fc57 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -840,6 +840,18 @@ struct drm_bridge { const struct drm_bridge_timings *timings; /** @funcs: control functions */ const struct drm_bridge_funcs *funcs; + + /** + * @container: Pointer to the private driver struct embedding this + * @struct drm_bridge. + */ + void *container; + + /** + * @refcount: reference count of users referencing this bridge. + */ + struct kref refcount; + /** @driver_private: pointer to the bridge driver's internal context */ void *driver_private; /** @ops: bitmask of operations supported by the bridge */ @@ -941,6 +953,9 @@ drm_priv_to_bridge(struct drm_private_obj *priv) return container_of(priv, struct drm_bridge, base); } +struct drm_bridge *drm_bridge_get(struct drm_bridge *bridge); +void drm_bridge_put(struct drm_bridge *bridge); + void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, const struct drm_bridge_funcs *funcs); @@ -951,6 +966,10 @@ void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, * @member: the name of the &drm_bridge within @type * @funcs: callbacks for this bridge * + * The reference count of the returned bridge is initialized to 1. This + * reference will be automatically dropped via devm (by calling + * drm_bridge_put()) when @dev is removed. + * * Returns: * Pointer to new bridge, or ERR_PTR on failure. */ From patchwork Wed Mar 26 17:47:37 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 14030431 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 4B1E2C3600E for ; Wed, 26 Mar 2025 17:55:19 +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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s=gm1; t=1743011283; 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=INhI5GY5KpAC1e+W0x4kcSuViX4iAnBipLvZsEs2/Fk=; b=IJjbYn/+SO/mrbDC/CF08v7B3Sw2MF+noNcWTp3Wj70f/uveC5LNeuQSjierBp62340XSm utadCLhc7w7zpJ1rWiD/Ixsls4qERj/rGGRi5r8wXHq00oIK8cBrwBaWFKEOSLaYkFf/zN CW4nHDDytGgu9Y41d2xVlCEbyOUCXFeyV8nw4ma9At4uWOLad3vyWZ3OaigutUzCNaOc+E O/04uIif1V3r0dyRr93/sWb/Kd6Ddh3pJ9CjyMtnDJlOMPyAqpQXGXPnkZVWuxaVi9BLnm OXmazCgphXS2c+GnIcCm9RMqt9ZmrgkBgccfcVRNh4bkTjax3QLWI6ytn3uT+Q== From: Luca Ceresoli Date: Wed, 26 Mar 2025 18:47:37 +0100 Subject: [PATCH v9 3/5] drm/bridge: make devm_drm_bridge_alloc() mandatory for bridge allocation MIME-Version: 1.0 Message-Id: <20250326-drm-bridge-refcount-v9-3-5e0661fe1f84@bootlin.com> References: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@bootlin.com> In-Reply-To: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@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: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdduieeiudejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredtjeenucfhrhhomhepnfhutggrucevvghrvghsohhlihcuoehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeiieeuvdfftefgueduleehueetgffgjeeitedtteetkeeuueeuueekveevvdeuveenucfkphepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgenucevlhhushhtvghrufhiiigvpedunecurfgrrhgrmhepihhnvghtpedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvpdhhvghloheplgduledvrdduieekrddujeekrdejhegnpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepfedupdhrtghpthhtohepmhgrrghrthgvnhdrlhgrnhhkhhhorhhstheslhhinhhugidrihhnthgvlhdrtghomhdprhgtphhtthhopehmrghrvgigseguvghngidruggvpdhrtghpthhtohepihhmgieslhhishhtshdrlhhinhhugidruggvvhdprhgtphhtt hhopefjuhhirdfruhesghgvhhgvrghlthhhtggrrhgvrdgtohhmpdhrtghpthhtohepshhimhhonhgrsehffhiflhhlrdgthhdprhgtphhtthhopehnvghilhdrrghrmhhsthhrohhngheslhhinhgrrhhordhorhhgpdhrtghpthhtoheprghirhhlihgvugesghhmrghilhdrtghomhdprhgtphhtthhopehhvghrvhgvrdgtohguihhnrgessghoohhtlhhinhdrtghomh X-GND-Sasl: luca.ceresoli@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250326_104804_878843_18EECC5B X-CRM114-Status: GOOD ( 10.67 ) 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 All DRM bridges are now supposed to be allocated using devm_drm_bridge_alloc(), which is cleaner and necessary to support refcounting. In the absence of a drm_bridge_init() or such initialization function, document the new mandatory alloc function on the first DRM bridge core function that is called after allocation, i.e. drm_bridge_add(). Suggested-by: Maxime Ripard Signed-off-by: Luca Ceresoli Reviewed-by: Maxime Ripard --- Changes in v9: - remove sentence about old-style allocation This patch was added in v8. --- drivers/gpu/drm/drm_bridge.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 22b459af112fd3cd2db00aa16668d270e028b307..b4c89ec01998b849018ce031c7cd84614e65e710 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -286,6 +286,9 @@ EXPORT_SYMBOL(__devm_drm_bridge_alloc); * drm_bridge_add - add the given bridge to the global bridge list * * @bridge: bridge control structure + * + * The bridge to be added must have been allocated by + * devm_drm_bridge_alloc(). */ void drm_bridge_add(struct drm_bridge *bridge) { From patchwork Wed Mar 26 17:47:38 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 14030432 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 9B2C3C36008 for ; 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Wed, 26 Mar 2025 17:56:55 +0000 Received: from relay8-d.mail.gandi.net ([217.70.183.201]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1txUrG-00000009Fyo-31Dr for linux-arm-kernel@lists.infradead.org; Wed, 26 Mar 2025 17:48:08 +0000 Received: by mail.gandi.net (Postfix) with ESMTPSA id 474944441C; Wed, 26 Mar 2025 17:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1743011285; 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=FzCa2zrAbheOTbL7Z1DIQWacnklnFI0a1ryUn/mz7c0=; b=PKe0GirU+LLt8flRiKK/pYhdiys9qYPxfgXHfHKxRrtN/m8vLr9kywoXjUzWb116szMYow Mjm+IfBSzbxJMxpjJjrhzXfyPTROGis3M5LJXwmDduF3qTi2beEZ0nwEHdJuhbUqGyMkNW vUZ7Bc+M1qgVDpJMT04F2LNO4xvB8I724Ymx7ytdPiiNwTQ/MdfXOohbDFrh+NywrZNYkf kVCpkPXTNj9tW8x+IxOmVdLBBYTsRqTs4Xjwc9SGRPsmLWVPmYjj1EbzbJECcg87A1l8ID UwMf9335RKmUXKt/Hkf6HhJiR0gAj2zqYyoxreeskxSGWreuPyxSDfp5c/sspg== From: Luca Ceresoli Date: Wed, 26 Mar 2025 18:47:38 +0100 Subject: [PATCH v9 4/5] drm/bridge: ti-sn65dsi83: use dynamic lifetime management MIME-Version: 1.0 Message-Id: <20250326-drm-bridge-refcount-v9-4-5e0661fe1f84@bootlin.com> References: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@bootlin.com> In-Reply-To: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@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: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdduieeiudejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredtjeenucfhrhhomhepnfhutggrucevvghrvghsohhlihcuoehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeiieeuvdfftefgueduleehueetgffgjeeitedtteetkeeuueeuueekveevvdeuveenucfkphepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgenucevlhhushhtvghrufhiiigvpedunecurfgrrhgrmhepihhnvghtpedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvpdhhvghloheplgduledvrdduieekrddujeekrdejhegnpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepfedupdhrtghpthhtohepmhgrrghrthgvnhdrlhgrnhhkhhhorhhstheslhhinhhugidrihhnthgvlhdrtghomhdprhgtphhtthhopehmrghrvgigseguvghngidruggvpdhrtghpthhtohepihhmgieslhhishhtshdrlhhinhhugidruggvvhdprhgtphhtt hhopefjuhhirdfruhesghgvhhgvrghlthhhtggrrhgvrdgtohhmpdhrtghpthhtohepshhimhhonhgrsehffhiflhhlrdgthhdprhgtphhtthhopehnvghilhdrrghrmhhsthhrohhngheslhhinhgrrhhordhorhhgpdhrtghpthhtoheprghirhhlihgvugesghhmrghilhdrtghomhdprhgtphhtthhopehhvghrvhgvrdgtohguihhnrgessghoohhtlhhinhdrtghomh X-GND-Sasl: luca.ceresoli@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250326_104806_894979_56402E19 X-CRM114-Status: GOOD ( 10.35 ) 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 Allow this bridge to be removable without dangling pointers and use-after-free, together with proper use of drm_bridge_get() and _put() by consumers. Reviewed-by: Maxime Ripard Signed-off-by: Luca Ceresoli --- Changes in v9: none Changes in v8: none Changes in v7: none Changed in v6: - Update to use devm_drm_bridge_alloc(), remove .destroy This patch was added in v5. --- drivers/gpu/drm/bridge/ti-sn65dsi83.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c index 6e0ba427c2582c33f7b95634a18dcda9ac28267f..4efb62376e196d8bb5e9f58867e5c0e1624391db 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c @@ -947,9 +947,9 @@ static int sn65dsi83_probe(struct i2c_client *client) struct sn65dsi83 *ctx; int ret; - ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL); - if (!ctx) - return -ENOMEM; + ctx = devm_drm_bridge_alloc(dev, struct sn65dsi83, bridge, &sn65dsi83_funcs); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); ctx->dev = dev; INIT_WORK(&ctx->reset_work, sn65dsi83_reset_work); @@ -989,7 +989,6 @@ static int sn65dsi83_probe(struct i2c_client *client) dev_set_drvdata(dev, ctx); i2c_set_clientdata(client, ctx); - ctx->bridge.funcs = &sn65dsi83_funcs; ctx->bridge.of_node = dev->of_node; ctx->bridge.pre_enable_prev_first = true; ctx->bridge.type = DRM_MODE_CONNECTOR_LVDS; From patchwork Wed Mar 26 17:47:39 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 14030433 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 D81A9C36008 for ; Wed, 26 Mar 2025 17:58:48 +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=1743011287; 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=0JsqmFLguGdHYdQCPsm7D7GBkBg/nRWv7oJAHkmWlfA=; b=at3aiMjvQc1mWBn1ozeshRGPzhub/ADj2TZLGwmcSnrctlqOmCMcGgos20+6VwvG/+83jj LoRpDwj2eiOvJt29UYtkrh94zDxo+g5/fGL9pDhG/xucno7uzDo9KoK8WN+0oP+o9lgoPH wU4/61agaod3UAlld6r8sHfrH0kwOExMJb9m2V3yFfm2V8a/JZupXT54C8xVJwS7kHHzkJ o278CvDDJEuW/R91zrMRI9vkknM8vzB46660GZWGYU0OfpOP/0u3jsqB1hsiTC2yqkjHBS Ifwso/XysQcyJeXH5EqJLoKrGnAaCcSK2W2dLewvw1NUiHoNgZP7usBRelUBBg== From: Luca Ceresoli Date: Wed, 26 Mar 2025 18:47:39 +0100 Subject: [PATCH v9 5/5] drm/bridge: samsung-dsim: use dynamic lifetime management MIME-Version: 1.0 Message-Id: <20250326-drm-bridge-refcount-v9-5-5e0661fe1f84@bootlin.com> References: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@bootlin.com> In-Reply-To: <20250326-drm-bridge-refcount-v9-0-5e0661fe1f84@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: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdduieeiudejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhfffugggtgffkfhgjvfevofesthejredtredtjeenucfhrhhomhepnfhutggrucevvghrvghsohhlihcuoehluhgtrgdrtggvrhgvshholhhisegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeiieeuvdfftefgueduleehueetgffgjeeitedtteetkeeuueeuueekveevvdeuveenucfkphepvdgrtddvmeeijedtmedvtddvtdemvggrtddumegsvgegudemleehvgejmeefgeefmeeludefvgenucevlhhushhtvghrufhiiigvpeefnecurfgrrhgrmhepihhnvghtpedvrgdtvdemieejtdemvddtvddtmegvrgdtudemsggvgedumeelhegvjeemfeegfeemledufegvpdhhvghloheplgduledvrdduieekrddujeekrdejhegnpdhmrghilhhfrhhomheplhhutggrrdgtvghrvghsohhlihessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepfedupdhrtghpthhtohepmhgrrghrthgvnhdrlhgrnhhkhhhorhhstheslhhinhhugidrihhnthgvlhdrtghomhdprhgtphhtthhopehmrghrvgigseguvghngidruggvpdhrtghpthhtohepihhmgieslhhishhtshdrlhhinhhugidruggvvhdprhgtphhtt hhopefjuhhirdfruhesghgvhhgvrghlthhhtggrrhgvrdgtohhmpdhrtghpthhtohepshhimhhonhgrsehffhiflhhlrdgthhdprhgtphhtthhopehnvghilhdrrghrmhhsthhrohhngheslhhinhgrrhhordhorhhgpdhrtghpthhtoheprghirhhlihgvugesghhmrghilhdrtghomhdprhgtphhtthhopehhvghrvhgvrdgtohguihhnrgessghoohhtlhhinhdrtghomh X-GND-Sasl: luca.ceresoli@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250326_104809_149004_B6EFAB22 X-CRM114-Status: UNSURE ( 9.77 ) X-CRM114-Notice: Please train this message. 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 Allow this bridge to be removable without dangling pointers and use-after-free, together with proper use of drm_bridge_get() and _put() by consumers. Reviewed-by: Maxime Ripard Signed-off-by: Luca Ceresoli --- Changes in v9: none Changes in v8: none This patch was added in v7. --- drivers/gpu/drm/bridge/samsung-dsim.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index 55ac6bd5da08c037aa7974df679d51e72bc54faf..0014c497e3fe7d8349a119dbdda30d65d816cccf 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -1936,9 +1936,9 @@ int samsung_dsim_probe(struct platform_device *pdev) struct samsung_dsim *dsi; int ret, i; - dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL); - if (!dsi) - return -ENOMEM; + dsi = devm_drm_bridge_alloc(dev, struct samsung_dsim, bridge, &samsung_dsim_bridge_funcs); + if (IS_ERR(dsi)) + return PTR_ERR(dsi); init_completion(&dsi->completed); spin_lock_init(&dsi->transfer_lock); @@ -2008,7 +2008,6 @@ int samsung_dsim_probe(struct platform_device *pdev) pm_runtime_enable(dev); - dsi->bridge.funcs = &samsung_dsim_bridge_funcs; dsi->bridge.of_node = dev->of_node; dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;