From patchwork Fri Apr 7 22:40:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 13205449 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 9A292C6FD1D for ; Fri, 7 Apr 2023 22:41:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231361AbjDGWlJ (ORCPT ); Fri, 7 Apr 2023 18:41:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231130AbjDGWlD (ORCPT ); Fri, 7 Apr 2023 18:41:03 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93083D532; Fri, 7 Apr 2023 15:40:57 -0700 (PDT) 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 337MVnGd003703; Fri, 7 Apr 2023 22:40:51 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=qcppdkim1; bh=mrzAxL+ALewHXGb7bTnfhweah2z2VemEqbRNLk/lNUA=; b=EDhvNrC2vRmKzX2DaLtrSZchJWldBnYY7XmI9tcT5ELJYn+01B1qVp9jOvxATZoZgcNS Uw1et7mv4iTZPxE/F47wYwLhqx94On3dUUDTTjJSwk6zNYd75YGTtyFrpcSicSwoSuhY o+09MGpDlafjyinmwCZFXfXuz7SI5l1eSgl/LVO7r+ynz2xP87LEdbhwTk6Zz1gIQbIg zpbJh2reFk9hjTRVYQnZh62OdZ5QmVzys9LGOLrYBa0W6wW3Axpw0lKt8PeDM7g2q22Q enS+BgTARtPx45JlskM51UIZ6DnWrnMM6yiJkSpCrRLULIdYC8TRw+DNP3sw1wTxg3k5 rQ== Received: from nalasppmta05.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3ptd5ct0sq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Apr 2023 22:40:51 +0000 Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 337Mecor019240 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 7 Apr 2023 22:40:38 GMT Received: from hu-wcheng-lv.qualcomm.com (10.49.16.6) by nalasex01b.na.qualcomm.com (10.47.209.197) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Fri, 7 Apr 2023 15:40:38 -0700 From: Wesley Cheng To: , CC: , , , , Wesley Cheng Subject: [PATCH v2 2/3] usb: dwc3: gadget: Stall and restart EP0 if host is unresponsive Date: Fri, 7 Apr 2023 15:40:24 -0700 Message-ID: <20230407224025.22315-3-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230407224025.22315-1-quic_wcheng@quicinc.com> References: <20230407224025.22315-1-quic_wcheng@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01b.na.qualcomm.com (10.47.209.197) To nalasex01b.na.qualcomm.com (10.47.209.197) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: imnr2LYMG9YbbuBOBvJCQTqzd8KrjN9d X-Proofpoint-ORIG-GUID: imnr2LYMG9YbbuBOBvJCQTqzd8KrjN9d X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-07_14,2023-04-06_03,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 bulkscore=0 adultscore=0 priorityscore=1501 suspectscore=0 lowpriorityscore=0 impostorscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 phishscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304070205 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org It was observed that there are hosts that may complete pending SETUP transactions before the stop active transfers and controller halt occurs, leading to lingering endxfer commands on DEPs on subsequent pullup/gadget start iterations. dwc3_gadget_ep_disable name=ep8in flags=0x3009 direction=1 dwc3_gadget_ep_disable name=ep4in flags=1 direction=1 dwc3_gadget_ep_disable name=ep3out flags=1 direction=0 usb_gadget_disconnect deactivated=0 connected=0 ret=0 The sequence shows that the USB gadget disconnect (dwc3_gadget_pullup(0)) routine completed successfully, allowing for the USB gadget to proceed with a USB gadget connect. However, if this occurs the system runs into an issue where: BUG: spinlock already unlocked on CPU spin_bug+0x0 dwc3_remove_requests+0x278 dwc3_ep0_out_start+0xb0 __dwc3_gadget_start+0x25c This is due to the pending endxfers, leading to gadget start (w/o lock held) to execute the remove requests, which will unlock the dwc3 spinlock as part of giveback. To mitigate this, resolve the pending endxfers on the pullup disable path by re-locating the SETUP phase check after stop active transfers, since that is where the DWC3_EP_DELAY_STOP is potentially set. This also allows for handling of a host that may be unresponsive by using the completion timeout to trigger the stall and restart for EP0. Fixes: c96683798e27 ("usb: dwc3: ep0: Don't prepare beyond Setup stage") Signed-off-by: Wesley Cheng --- drivers/usb/dwc3/gadget.c | 42 +++++++++++++++++++++++---------------- 1 file changed, 25 insertions(+), 17 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 320e30476c88..91768f1bdbaf 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2546,29 +2546,17 @@ static int __dwc3_gadget_start(struct dwc3 *dwc); static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc) { unsigned long flags; + int ret; spin_lock_irqsave(&dwc->lock, flags); dwc->connected = false; /* - * Per databook, when we want to stop the gadget, if a control transfer - * is still in process, complete it and get the core into setup phase. + * Attempt to end pending SETUP status phase, and not wait for the + * function to do so. */ - if (dwc->ep0state != EP0_SETUP_PHASE) { - int ret; - - if (dwc->delayed_status) - dwc3_ep0_send_delayed_status(dwc); - - reinit_completion(&dwc->ep0_in_setup); - - spin_unlock_irqrestore(&dwc->lock, flags); - ret = wait_for_completion_timeout(&dwc->ep0_in_setup, - msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT)); - spin_lock_irqsave(&dwc->lock, flags); - if (ret == 0) - dev_warn(dwc->dev, "timed out waiting for SETUP phase\n"); - } + if (dwc->delayed_status) + dwc3_ep0_send_delayed_status(dwc); /* * In the Synopsys DesignWare Cores USB3 Databook Rev. 3.30a @@ -2581,6 +2569,26 @@ static int dwc3_gadget_soft_disconnect(struct dwc3 *dwc) __dwc3_gadget_stop(dwc); spin_unlock_irqrestore(&dwc->lock, flags); + /* + * Per databook, when we want to stop the gadget, if a control transfer + * is still in process, complete it and get the core into setup phase. + * In case the host is unresponsive to a SETUP transaction, forcefully + * stall the transfer, and move back to the SETUP phase, so that any + * pending endxfers can be executed. + */ + if (dwc->ep0state != EP0_SETUP_PHASE) { + reinit_completion(&dwc->ep0_in_setup); + + ret = wait_for_completion_timeout(&dwc->ep0_in_setup, + msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT)); + if (ret == 0) { + dev_warn(dwc->dev, "wait for SETUP phase timed out\n"); + spin_lock_irqsave(&dwc->lock, flags); + dwc3_ep0_reset_state(dwc); + spin_unlock_irqrestore(&dwc->lock, flags); + } + } + /* * Note: if the GEVNTCOUNT indicates events in the event buffer, the * driver needs to acknowledge them before the controller can halt.