From patchwork Tue Jan 10 07:12:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jack Pham X-Patchwork-Id: 13094766 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 2899AC46467 for ; Tue, 10 Jan 2023 07:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231166AbjAJHND (ORCPT ); Tue, 10 Jan 2023 02:13:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230161AbjAJHNB (ORCPT ); Tue, 10 Jan 2023 02:13:01 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3840E45659 for ; Mon, 9 Jan 2023 23:13:00 -0800 (PST) Received: from pps.filterd (m0279868.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30A5ulGG015301; Tue, 10 Jan 2023 07:12:57 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=qcppdkim1; bh=HbjkBDeFK1UPQ6gRVAgvnvUeEi58krsIsmQ7Kt1jPPU=; b=laL+PQdT3Ky871bA2vIZvcXYCbRUxtCIJvjj0uMcAi81KA2D8D+oW8DaQCerlRAh12Rq oKFgixZEaGOqXJvSKM/gklDvbHxHHgRjwvIoCvOQfqFMNSApTtv24x6rFk2psoGcGflq U4Ju7opg/31kB1KyPk3npXrfqxpETkiZrdFGEeK0hPwuo9QMGAwmjY1RPlQyzIeBz5n0 exqIUlgHjCWfHA2leSjBxpwSw0zd+l12kp41zJciXIYg6DsJe5SQccVcUKWNfLNTWsMC 7DjaOdaxhv0csFeaQmhKHP/IINu0w4kSKCuRk0uARGIsX7JOxm1MQoH4CrWuwlYOsuYG Tg== Received: from nalasppmta04.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3n0ssh914m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 Jan 2023 07:12:57 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 30A7Cu4Y007434 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 Jan 2023 07:12:56 GMT Received: from jackp-linux.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.36; Mon, 9 Jan 2023 23:12:55 -0800 From: Jack Pham To: Heikki Krogerus , Greg Kroah-Hartman CC: , Wesley Cheng , Subbaraman Narayanamurthy , Fenglin Wu , Jack Pham , Linyu Yuan Subject: [PATCH v3] usb: ucsi: Ensure connector delayed work items are flushed Date: Mon, 9 Jan 2023 23:12:18 -0800 Message-ID: <20230110071218.26261-1-quic_jackp@quicinc.com> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: uORD-iubgRj0UXf6QYTjxFtIFgk9iXnW X-Proofpoint-ORIG-GUID: uORD-iubgRj0UXf6QYTjxFtIFgk9iXnW X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.923,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2023-01-10_02,2023-01-09_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 lowpriorityscore=0 priorityscore=1501 phishscore=0 spamscore=0 clxscore=1015 suspectscore=0 adultscore=0 impostorscore=0 bulkscore=0 malwarescore=0 mlxlogscore=858 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2301100047 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org During ucsi_unregister() when destroying a connector's workqueue, there may still be pending delayed work items that haven't been scheduled yet. Because queue_delayed_work() uses a separate timer to schedule a work item, the destroy_workqueue() call is not aware of any pending items. Hence when a pending item's timer expires it would then try to queue on a dangling workqueue pointer. Fix this by keeping track of all work items in a list, so that prior to destroying the workqueue any pending items can be flushed. Do this by calling mod_delayed_work() as that will cause pending items to get queued immediately, which then allows the ensuing destroy_workqueue() to implicitly drain all currently queued items to completion and free themselves. Fixes: b9aa02ca39a4 ("usb: typec: ucsi: Add polling mechanism for partner tasks like alt mode checking") Suggested-by: Heikki Krogerus Co-developed-by: Linyu Yuan Signed-off-by: Linyu Yuan Signed-off-by: Jack Pham Reviewed-by: Heikki Krogerus --- v3: Adopted Heikki's suggestion to track work items in a list. Updated subject and commit description again. v2: update commit description and remove cc stable list drivers/usb/typec/ucsi/ucsi.c | 24 +++++++++++++++++++++--- drivers/usb/typec/ucsi/ucsi.h | 1 + 2 files changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index eabe519013e7..1292241d581a 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -187,6 +187,7 @@ EXPORT_SYMBOL_GPL(ucsi_send_command); struct ucsi_work { struct delayed_work work; + struct list_head node; unsigned long delay; unsigned int count; struct ucsi_connector *con; @@ -202,6 +203,7 @@ static void ucsi_poll_worker(struct work_struct *work) mutex_lock(&con->lock); if (!con->partner) { + list_del(&uwork->node); mutex_unlock(&con->lock); kfree(uwork); return; @@ -209,10 +211,12 @@ static void ucsi_poll_worker(struct work_struct *work) ret = uwork->cb(con); - if (uwork->count-- && (ret == -EBUSY || ret == -ETIMEDOUT)) + if (uwork->count-- && (ret == -EBUSY || ret == -ETIMEDOUT)) { queue_delayed_work(con->wq, &uwork->work, uwork->delay); - else + } else { + list_del(&uwork->node); kfree(uwork); + } mutex_unlock(&con->lock); } @@ -236,6 +240,7 @@ static int ucsi_partner_task(struct ucsi_connector *con, uwork->con = con; uwork->cb = cb; + list_add_tail(&uwork->node, &con->partner_tasks); queue_delayed_work(con->wq, &uwork->work, delay); return 0; @@ -1056,6 +1061,7 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) INIT_WORK(&con->work, ucsi_handle_connector_change); init_completion(&con->complete); mutex_init(&con->lock); + INIT_LIST_HEAD(&con->partner_tasks); con->num = index + 1; con->ucsi = ucsi; @@ -1420,8 +1426,20 @@ void ucsi_unregister(struct ucsi *ucsi) ucsi_unregister_altmodes(&ucsi->connector[i], UCSI_RECIPIENT_CON); ucsi_unregister_port_psy(&ucsi->connector[i]); - if (ucsi->connector[i].wq) + + if (ucsi->connector[i].wq) { + struct ucsi_work *uwork; + + mutex_lock(&ucsi->connector[i].lock); + /* + * queue delayed items immediately so they can execute + * and free themselves before the wq is destroyed + */ + list_for_each_entry(uwork, &ucsi->connector[i].partner_tasks, node) + mod_delayed_work(ucsi->connector[i].wq, &uwork->work, 0); + mutex_unlock(&ucsi->connector[i].lock); destroy_workqueue(ucsi->connector[i].wq); + } typec_unregister_port(ucsi->connector[i].port); } diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h index c968474ee547..60ce9fb6e745 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -322,6 +322,7 @@ struct ucsi_connector { struct work_struct work; struct completion complete; struct workqueue_struct *wq; + struct list_head partner_tasks; struct typec_port *port; struct typec_partner *partner;