From patchwork Mon Mar 18 17:49:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 10858371 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6A4E21709 for ; Mon, 18 Mar 2019 17:49:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4E74F2522B for ; Mon, 18 Mar 2019 17:49:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4CBE5286B5; Mon, 18 Mar 2019 17:49:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 25DFC286A8 for ; Mon, 18 Mar 2019 17:49:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726812AbfCRRtP (ORCPT ); Mon, 18 Mar 2019 13:49:15 -0400 Received: from foss.arm.com ([217.140.101.70]:39044 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726623AbfCRRtP (ORCPT ); Mon, 18 Mar 2019 13:49:15 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 0CB16EBD; Mon, 18 Mar 2019 10:49:15 -0700 (PDT) Received: from why.lan (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id ADD583F614; Mon, 18 Mar 2019 10:49:13 -0700 (PDT) From: Marc Zyngier To: Guenter Roeck , Heikki Krogerus , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] usb: typec: fusb302: Fix debugfs mutex initialisation Date: Mon, 18 Mar 2019 17:49:06 +0000 Message-Id: <20190318174906.10429-1-marc.zyngier@arm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Running a kernel with the fusb302 driver and lockdep enabled leads to an unpleasant warning: [ 4.617477] INFO: trying to register non-static key. [ 4.617930] the code is fine but needs lockdep annotation. [ 4.618418] turning off the locking correctness validator. [ 4.618913] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.1.0-rc1-00007-g3542533f3fc9 #13 [ 4.619620] Hardware name: rockchip evb_rk3399/evb_rk3399, BIOS 2019.04-rc3-00124-g2feec69fb1 03/15/2019 [ 4.620454] Call trace: [ 4.620693] dump_backtrace+0x0/0x138 [ 4.621028] show_stack+0x24/0x30 [ 4.621336] dump_stack+0xbc/0x104 [ 4.621649] register_lock_class+0x594/0x598 [ 4.622036] __lock_acquire+0x80/0x11b8 [ 4.622384] lock_acquire+0xdc/0x260 [ 4.622711] __mutex_lock+0x90/0x8a0 [ 4.623037] mutex_lock_nested+0x3c/0x50 [ 4.623394] _fusb302_log+0x88/0x1f0 [ 4.623721] fusb302_log+0x7c/0xa0 [ 4.624033] tcpm_init+0x5c/0x190 [ 4.624336] tcpm_init+0x3c/0x130 [ 4.624640] tcpm_register_port+0x574/0x878 [ 4.625019] fusb302_probe+0x2c8/0x590 Despite what the message says, the code isn't fine, as it tries to make use of the fusb302_log facility pretty early. This requires the logbuffer_lock mutex to be initialised, but that only happens much later. Boo. Hoist the fusb302_debugfs_init call before tcpm_register_port so that we can enjoy a working mutex. At Guenter's request, also add teardown of the debugfs facility on the error path. Signed-off-by: Marc Zyngier Reviewed-by: Guenter Roeck --- drivers/usb/typec/tcpm/fusb302.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c index e9344997329c..76cb8be6f3eb 100644 --- a/drivers/usb/typec/tcpm/fusb302.c +++ b/drivers/usb/typec/tcpm/fusb302.c @@ -1790,12 +1790,13 @@ static int fusb302_probe(struct i2c_client *client, goto destroy_workqueue; } + fusb302_debugfs_init(chip); chip->tcpm_port = tcpm_register_port(&client->dev, &chip->tcpc_dev); if (IS_ERR(chip->tcpm_port)) { ret = PTR_ERR(chip->tcpm_port); if (ret != -EPROBE_DEFER) dev_err(dev, "cannot register tcpm port, ret=%d", ret); - goto destroy_workqueue; + goto unregister_debugfs; } ret = devm_request_threaded_irq(chip->dev, chip->gpio_int_n_irq, @@ -1807,13 +1808,14 @@ static int fusb302_probe(struct i2c_client *client, goto tcpm_unregister_port; } enable_irq_wake(chip->gpio_int_n_irq); - fusb302_debugfs_init(chip); i2c_set_clientdata(client, chip); return ret; tcpm_unregister_port: tcpm_unregister_port(chip->tcpm_port); +unregister_debugfs: + fusb302_debugfs_exit(chip); destroy_workqueue: destroy_workqueue(chip->wq);