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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5384CC11F67 for ; Wed, 14 Jul 2021 10:13:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A1B26100B for ; Wed, 14 Jul 2021 10:13:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239054AbhGNKQs (ORCPT ); Wed, 14 Jul 2021 06:16:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239008AbhGNKQr (ORCPT ); Wed, 14 Jul 2021 06:16:47 -0400 Received: from laurent.telenet-ops.be (laurent.telenet-ops.be [IPv6:2a02:1800:110:4::f00:19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1624C061762 for ; Wed, 14 Jul 2021 03:13:55 -0700 (PDT) Received: from ramsan.of.borg ([IPv6:2a02:1810:ac12:ed10:39cc:190a:2775:cfe7]) by laurent.telenet-ops.be with bizsmtp id UyDr2500c1ccfby01yDrca; Wed, 14 Jul 2021 12:13:54 +0200 Received: from rox.of.borg ([192.168.97.57]) by ramsan.of.borg with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1m3btn-0016Zx-IJ; Wed, 14 Jul 2021 12:13:51 +0200 Received: from geert by rox.of.borg with local (Exim 4.93) (envelope-from ) id 1m3btm-00A6LB-O2; Wed, 14 Jul 2021 12:13:50 +0200 From: Geert Uytterhoeven To: Greg Kroah-Hartman , "Rafael J . Wysocki" , Kevin Hilman , Ulf Hansson Cc: Saravana Kannan , Bartosz Golaszewski , Magnus Damm , linux-renesas-soc@vger.kernel.org, linux-pm@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH v2] staging: board: Fix uninitialized spinlock when attaching genpd Date: Wed, 14 Jul 2021 12:13:46 +0200 Message-Id: <57783ece7ddae55f2bda2f59f452180bff744ea0.1626257398.git.geert+renesas@glider.be> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Armadillo-800-EVA with CONFIG_DEBUG_SPINLOCK=y: BUG: spinlock bad magic on CPU#0, swapper/1 lock: lcdc0_device+0x10c/0x308, .magic: 00000000, .owner: /-1, .owner_cpu: 0 CPU: 0 PID: 1 Comm: swapper Not tainted 5.11.0-rc5-armadillo-00036-gbbca04be7a80-dirty #287 Hardware name: Generic R8A7740 (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (do_raw_spin_lock+0x20/0x94) [] (do_raw_spin_lock) from [] (dev_pm_get_subsys_data+0x8c/0x11c) [] (dev_pm_get_subsys_data) from [] (genpd_add_device+0x78/0x2b8) [] (genpd_add_device) from [] (of_genpd_add_device+0x34/0x4c) [] (of_genpd_add_device) from [] (board_staging_register_device+0x11c/0x148) [] (board_staging_register_device) from [] (board_staging_register_devices+0x24/0x28) of_genpd_add_device() is called before platform_device_register(), as it needs to attach the genpd before the device is probed. But the spinlock is only initialized when the device is registered. Fix this by open-coding the spinlock initialization, cfr. device_pm_init_common() in the internal drivers/base code, and in the SuperH early platform code. Signed-off-by: Geert Uytterhoeven --- Exposed by fw_devlinks changing probe order. Masked before due to an unrelated wait context check failure, which disabled any further spinlock checks. https://lore.kernel.org/linux-acpi/CAMuHMdVL-1RKJ5u-HDVA4F4w_+8yGvQQuJQBcZMsdV4yXzzfcw@mail.gmail.com v2: - Improve code comment. --- drivers/staging/board/board.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/staging/board/board.c b/drivers/staging/board/board.c index cb6feb34dd401ae3..f980af0373452cab 100644 --- a/drivers/staging/board/board.c +++ b/drivers/staging/board/board.c @@ -136,6 +136,7 @@ int __init board_staging_register_clock(const struct board_staging_clk *bsc) static int board_staging_add_dev_domain(struct platform_device *pdev, const char *domain) { + struct device *dev = &pdev->dev; struct of_phandle_args pd_args; struct device_node *np; @@ -148,7 +149,11 @@ static int board_staging_add_dev_domain(struct platform_device *pdev, pd_args.np = np; pd_args.args_count = 0; - return of_genpd_add_device(&pd_args, &pdev->dev); + /* Initialization similar to device_pm_init_common() */ + spin_lock_init(&dev->power.lock); + dev->power.early_init = true; + + return of_genpd_add_device(&pd_args, dev); } #else static inline int board_staging_add_dev_domain(struct platform_device *pdev, -- 2.25.1