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 77AE1CD342C for ; Mon, 4 May 2026 10:45:34 +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: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; bh=klEnOYxwmyhP43dH3LhaM6WGup/8KCXunSlgbkKjiG0=; b=XlXHw4m9f7wW7cDQv11T8I9n+4 XTHHaix35P9fv4M3mFkwix9OFU7c1Wswc3POcvbsIIIpaDb8k1ubLedvWjGSSmxe5tMyaIgI+uulf RaiRao61y9D5t8Sv0ZY2qesRRAEq4lIZlAOks1DevYHRVyO4fpmF7DVMTjwKE7DzA9wKnPePbeFWt uqxryj6PcGsj8SIunMKThlnXF5khOyMJhtjGcPn38LXpTXyaWtEgYjs77Fo1Cp/q5UC1vmhRxUTrF IV1Xp0fEKiZEDHx/3rd67mS0nalD3jKFy4BEffIiCFoWxnk24rXJf8OHr+HzV2zySwNrVFiSFUV4M kUEXgvPA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wJqno-0000000CxYH-0KxL; Mon, 04 May 2026 10:45:28 +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 1wJqnl-0000000CxXb-1lHh for linux-arm-kernel@lists.infradead.org; Mon, 04 May 2026 10:45:27 +0000 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 0312E4E42BBD; Mon, 4 May 2026 10:45:24 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id C7CA75FD5F; Mon, 4 May 2026 10:45:23 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 302A211AD268B; Mon, 4 May 2026 12:45:18 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1777891522; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=klEnOYxwmyhP43dH3LhaM6WGup/8KCXunSlgbkKjiG0=; b=J1bP7p5jLRAg4yL8WnncjKCDTZOj3ZAmRZEkdaNKTsHWgSFlmnGYxSRH6NnxbcF3+mjzwB zTOaH9kSr/PP6nhe86m8Epojv57ra2ZTCBZVSldj38oAYD5+frkyg3NkGc5usfJBqZBMaD 90oULpBA4oX8S68g8mOgEXoJMf45WM9AUMFFdKconV/NE2c8D4RvI0eY4xEp4FWJl7dzx3 7sQmaW8+VZRLUf16TgKsoU83BaJf46ctk123nu78CwoUzTIwP1GxWMTWPADT2y85ramMjx LetAO3dfS8Ycrmi8Bj2QA2G5kyTA0QEtoPVIL7dTDmebjm/aEg285JChhzLaAw== From: Luca Ceresoli Date: Mon, 04 May 2026 12:45:04 +0200 Subject: [PATCH v4 01/11] drm/bridge: drm_bridge_get/put(): ignore ERR_PTR MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260504-drm-bridge-alloc-getput-panel_or_bridge-v4-1-b578c3daaf10@bootlin.com> References: <20260504-drm-bridge-alloc-getput-panel_or_bridge-v4-0-b578c3daaf10@bootlin.com> In-Reply-To: <20260504-drm-bridge-alloc-getput-panel_or_bridge-v4-0-b578c3daaf10@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 , 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 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_034525_881709_B4DA1AD7 X-CRM114-Status: GOOD ( 10.86 ) 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 Most functions returning a struct drm_bridge pointer currently return a valid pointer or NULL, but this restricts their ability to return an error code describing the error kind. In preparation to have new APIs that can return a struct drm_bridge pointer holding an ERR_PTR (and for those which already do) make drm_bridge_get() and drm_bridge_put() ignore ERR_PTR values, just like they ignore NULL pointers. This will avoid annoying error checking in many places and the risk of missing error checks. Suggested-by: Laurent Pinchart Link: https://lore.kernel.org/all/20260318152533.GA633439@killaraus.ideasonboard.com/ Suggested-by: Dmitry Baryshkov Link: https://lore.kernel.org/all/omlnswxukeqgnatzdvooaashgkfcacjevkvbkm6xt33itgua2k@jcmzll2w6kdq/ Reviewed-by: Dmitry Baryshkov Signed-off-by: Luca Ceresoli --- Changes in v4: - removed incorrect change to drm_bridge_clear_and_put() kdoc Patch added in v2 --- drivers/gpu/drm/drm_bridge.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index d4b3478258ec..6fb71de6d22a 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -282,7 +282,7 @@ static void __drm_bridge_free(struct kref *kref) /** * drm_bridge_get - Acquire a bridge reference - * @bridge: DRM bridge; if NULL this function does nothing + * @bridge: DRM bridge; if NULL or an ERR_PTR this function does nothing * * This function increments the bridge's refcount. * @@ -291,7 +291,7 @@ static void __drm_bridge_free(struct kref *kref) */ struct drm_bridge *drm_bridge_get(struct drm_bridge *bridge) { - if (bridge) + if (!IS_ERR_OR_NULL(bridge)) kref_get(&bridge->refcount); return bridge; @@ -300,7 +300,7 @@ EXPORT_SYMBOL(drm_bridge_get); /** * drm_bridge_put - Release a bridge reference - * @bridge: DRM bridge; if NULL this function does nothing + * @bridge: DRM bridge; if NULL or an ERR_PTR this function does nothing * * This function decrements the bridge's reference count and frees the * object if the reference count drops to zero. @@ -310,7 +310,7 @@ EXPORT_SYMBOL(drm_bridge_get); */ void drm_bridge_put(struct drm_bridge *bridge) { - if (bridge) + if (!IS_ERR_OR_NULL(bridge)) kref_put(&bridge->refcount, __drm_bridge_free); } EXPORT_SYMBOL(drm_bridge_put); -- 2.53.0