From patchwork Tue Apr 4 13:31:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Alexis_Lothor=C3=A9_=28eBPF_Foundation=29?= X-Patchwork-Id: 13200063 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA09FC6FD1D for ; Tue, 4 Apr 2023 13:36:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235261AbjDDNeg (ORCPT ); Tue, 4 Apr 2023 09:34:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235237AbjDDNeY (ORCPT ); Tue, 4 Apr 2023 09:34:24 -0400 Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1478649CE; Tue, 4 Apr 2023 06:33:59 -0700 (PDT) Received: (Authenticated sender: alexis.lothore@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 6B34AE000B; Tue, 4 Apr 2023 13:33:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1680615238; 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=Mo3HjqG41gQvCICstu9RcQV968d5yyBtvPhjoFmW600=; b=GxlHdy4eBR/YbPceBaocXsvSxmEp3u/fxMIh5Dfb7A4Bd5lliBXi5bYo8oWgLeEEAY1IR6 1g/7+TL7i91+ve8ld8/wrQ8JExZ21LTjjzHhshte3ZXRryQqRpVJnNnjdCti5JiE/4HO7z aYCg7r9U0lFDOkcJ1azl8GuYvArkws8O682QhF2tqfvD5LB4ZSnYpZfUnRQ59Adeqk6qs+ 4g8K6YtgbypzAVxcGf/MZTx1DR4XC+CrrGkpB+M8Di1DavMH5M1SmpzeGyqDYH4fXP47ca u5D7zA7OEkzMdid0Ys2itN2N6XDwcxl9xPhOUfnw+uWSIqN8qXZdSliDFq+Bcw== From: alexis.lothore@bootlin.com To: mdf@kernel.org, hao.wu@intel.com, yilun.xu@intel.com, trix@redhat.com, russell.h.weight@intel.com, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org Cc: thomas.petazzoni@bootlin.com, nicolas.carrier@orolia.com Subject: [PATCH] fpga: bridge: properly initialize bridge device before populating children Date: Tue, 4 Apr 2023 15:31:02 +0200 Message-Id: <20230404133102.2837535-2-alexis.lothore@bootlin.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230404133102.2837535-1-alexis.lothore@bootlin.com> References: <20230404133102.2837535-1-alexis.lothore@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org From: Alexis Lothoré The current code path can lead to warnings because of uninitialized device, which contains, as a consequence, uninitialized kobject. The uninitialized device is passed to of_platform_populate, which will at some point, while creating child device, try to get a reference on uninitialized parent, resulting in the following warning: kobject: '(null)' ((ptrval)): is not initialized, yet kobject_get() is being called. The warning is observed after migrating a kernel 5.10.x to 6.1.x. Reverting commit 0d70af3c2530 ("fpga: bridge: Use standard dev_release for class driver") seems to remove the warning. This commit aggregates device_initialize() and device_add() into device_register() but this new call is done AFTER of_platform_populate Fixes: 0d70af3c2530 ("fpga: bridge: Use standard dev_release for class driver") Signed-off-by: Alexis Lothoré Acked-by: Xu Yilun --- drivers/fpga/fpga-bridge.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c index 727704431f61..13918c8c839e 100644 --- a/drivers/fpga/fpga-bridge.c +++ b/drivers/fpga/fpga-bridge.c @@ -360,7 +360,6 @@ fpga_bridge_register(struct device *parent, const char *name, bridge->dev.parent = parent; bridge->dev.of_node = parent->of_node; bridge->dev.id = id; - of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev); ret = dev_set_name(&bridge->dev, "br%d", id); if (ret) @@ -372,6 +371,8 @@ fpga_bridge_register(struct device *parent, const char *name, return ERR_PTR(ret); } + of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev); + return bridge; error_device: