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 B7D47FF8870 for ; Tue, 28 Apr 2026 09:16:23 +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=9eo/paXSzW8BfmZpRrcP3BLHcobk12GzzlOo9kVEISI=; b=H7cjHoQjXXDSKoYXEJoljt22HX jjFRrKuoPkj6L9+xFsGtPcp2yTlPxNxi+3X0ovbzXBhlmZFtZMsn6IAKl9cIiTibFVX8lkXf+6B1u 4rtd5BVPy9P/8Gx1VvcN7a9oPwhrKnrQ8a4REZOUkDTxvoKvv2IEyMgmEMp1ZFvBXgoF0g/nONyuY Kp1eYiIHd73kv7p0uV0NMZx4wn14/vS9dv6rFWWPry2R0IfchuO6iNsU2pgbd3g+3jwnuE/cQsB9M gR5flxWw87ITYIsqhUP4cl+BIeor8cjdHs2dkCaikewUcfFiOd9K2uOAUwo12v9s9vVrNL1MJrRPM pc0Y3fHA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHeYG-000000013am-3Rkq; Tue, 28 Apr 2026 09:16:20 +0000 Received: from smtpout-02.galae.net ([185.246.84.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wHeYD-000000013YV-3T8P for linux-arm-kernel@lists.infradead.org; Tue, 28 Apr 2026 09:16:19 +0000 Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 505641A346B; Tue, 28 Apr 2026 09:16:15 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 1C9D3601D0; Tue, 28 Apr 2026 09:16:15 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 1E8C610728631; Tue, 28 Apr 2026 11:16:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1777367772; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=9eo/paXSzW8BfmZpRrcP3BLHcobk12GzzlOo9kVEISI=; b=gZtWpc3ZSRRnd4uPBXmVObuxc8b70mdizyNzto8rtZS1uImrEoGxPYW2eTiuMOOfzCqDjp Gw8wYAtxuRZInF9j7CBINLwawUlx+8x6aem3/QfVJSj+bmiTPXWXg0kTLu3vZUieVtk2wM n6ut4ZYM14a13BLpseFPBxKlMdcLVd88zkxJCzwIRgDx3f/fxoRgL02agg+PJ56wJPxsf1 vuXmJAoFzrhpr9gWE4FcL7Df2HczNsU97jnIx+AXD3Uw89/vzRdru5i8q3lVsrAgd5vMQn 0qdgr8ZQW+Fq2cevjahutli9RnM0D2qEv45DR87Eo1ZksS86gKaeuFbz1KsukA== From: Luca Ceresoli Date: Tue, 28 Apr 2026 11:15:47 +0200 Subject: [PATCH v2 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: <20260428-drm-bridge-alloc-getput-panel_or_bridge-v2-1-4300744a1c47@bootlin.com> References: <20260428-drm-bridge-alloc-getput-panel_or_bridge-v2-0-4300744a1c47@bootlin.com> In-Reply-To: <20260428-drm-bridge-alloc-getput-panel_or_bridge-v2-0-4300744a1c47@bootlin.com> To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Clark , Dmitry Baryshkov , Abhinav Kumar , Jessica Zhang , Sean Paul , Marijn Suijten , Tian Tao , Xinwei Kong , Sumit Semwal , John Stultz , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , 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-20260428_021618_017747_E7E6A47B X-CRM114-Status: GOOD ( 11.61 ) 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/ Signed-off-by: Luca Ceresoli --- Patch added in v2 --- drivers/gpu/drm/drm_bridge.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 986e4c79a4e0..cea5babbe99e 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); @@ -319,8 +319,8 @@ EXPORT_SYMBOL(drm_bridge_put); * drm_bridge_clear_and_put - Given a bridge pointer, clear the pointer * then put the bridge * @bridge_pp: pointer to pointer to a struct drm_bridge; ``bridge_pp`` - * must be non-NULL; if ``*bridge_pp`` is NULL this function - * does nothing + * must be non-NULL; if ``*bridge_pp`` is NULL or an ERR_PTR + * this function does nothing * * Helper to put a DRM bridge, but only after setting its pointer to * NULL. Useful when a struct drm_bridge reference must be dropped without -- 2.53.0