From patchwork Tue Sep 11 10:10:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heikki Krogerus X-Patchwork-Id: 10595369 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 29F2B1575 for ; Tue, 11 Sep 2018 10:10:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1A7F428F19 for ; Tue, 11 Sep 2018 10:10:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0F2CD29008; Tue, 11 Sep 2018 10:10:53 +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 B03F028F19 for ; Tue, 11 Sep 2018 10:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726798AbeIKPJ2 (ORCPT ); Tue, 11 Sep 2018 11:09:28 -0400 Received: from mga18.intel.com ([134.134.136.126]:19099 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726559AbeIKPJ2 (ORCPT ); Tue, 11 Sep 2018 11:09:28 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2018 03:10:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,360,1531810800"; d="scan'208";a="88991813" Received: from black.fi.intel.com (HELO black.fi.intel.com.) ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 11 Sep 2018 03:10:49 -0700 From: Heikki Krogerus To: Hans de Goede , Greg Kroah-Hartman Cc: Andy Shevchenko , Darren Hart , platform-driver-x86@vger.kernel.org, linux-usb@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH v4 02/10] usb: roles: Handle driver reference counting Date: Tue, 11 Sep 2018 13:10:36 +0300 Message-Id: <20180911101044.44004-3-heikki.krogerus@linux.intel.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180911101044.44004-1-heikki.krogerus@linux.intel.com> References: <20180911101044.44004-1-heikki.krogerus@linux.intel.com> 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 This fixes potential "BUG: unable to handle kernel paging request at ..." from happening. Fixes: fde0aa6c175a ("usb: common: Small class for USB role switches") Cc: Signed-off-by: Heikki Krogerus --- drivers/usb/common/roles.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/usb/common/roles.c b/drivers/usb/common/roles.c index 15cc76e22123..99116af07f1d 100644 --- a/drivers/usb/common/roles.c +++ b/drivers/usb/common/roles.c @@ -109,8 +109,15 @@ static void *usb_role_switch_match(struct device_connection *con, int ep, */ struct usb_role_switch *usb_role_switch_get(struct device *dev) { - return device_connection_find_match(dev, "usb-role-switch", NULL, - usb_role_switch_match); + struct usb_role_switch *sw; + + sw = device_connection_find_match(dev, "usb-role-switch", NULL, + usb_role_switch_match); + + if (!IS_ERR_OR_NULL(sw)) + WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); + + return sw; } EXPORT_SYMBOL_GPL(usb_role_switch_get); @@ -122,8 +129,10 @@ EXPORT_SYMBOL_GPL(usb_role_switch_get); */ void usb_role_switch_put(struct usb_role_switch *sw) { - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { put_device(&sw->dev); + module_put(sw->dev.parent->driver->owner); + } } EXPORT_SYMBOL_GPL(usb_role_switch_put);