From patchwork Mon Apr 10 23:19:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 672271 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 DCEADC77B73 for ; Mon, 10 Apr 2023 23:20:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229897AbjDJXUN (ORCPT ); Mon, 10 Apr 2023 19:20:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229727AbjDJXUL (ORCPT ); Mon, 10 Apr 2023 19:20:11 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 183071717; Mon, 10 Apr 2023 16:20:10 -0700 (PDT) Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 33ANFds3030501; Mon, 10 Apr 2023 23:20:07 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=RfKvcaLirDRvCfLPByLggfS+B4A7qjBJpEEtwksOkNKlbX23eG/pD6Ghw+T587Ts3rqJ 5qfqgfVlIIZLAvnq0MwQxuB8Vq6UgGQuevatGMUmyOSzkG/5C6ad6DJy2ub26x6Wbw4v VPPpcefDPiWtPLloz3PgNNsJ3uoiio+rUMbZhmf/u0Sj6tLUULP5Re/KL0mKtpyFzknC DHmPqZvK5oMl4Ln449cj1l+sJoFDgF4FB2yH5v9N8wTjDQ0AjOTMjhbqPkFhEvwNvtVv 9jWdvwCRjujtX3SJKFgpp4lM+54Rp9MuVILqyDD+B3MjqvfAgAewQUWc9IuKXekaDhbi SA== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3pvq4dgga6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Apr 2023 23:20:07 +0000 Received: from nalasex01b.na.qualcomm.com (nalasex01b.na.qualcomm.com [10.47.209.197]) by NALASPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 33ANK6e8029460 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Apr 2023 23:20:06 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; Mon, 10 Apr 2023 16:20:05 -0700 From: Wesley Cheng To: , CC: , , , , Wesley Cheng Subject: [PATCH v3 2/3] usb: dwc3: gadget: Stall and restart EP0 if host is unresponsive Date: Mon, 10 Apr 2023 16:19:53 -0700 Message-ID: <20230410231954.437-3-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230410231954.437-1-quic_wcheng@quicinc.com> References: <20230410231954.437-1-quic_wcheng@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01c.na.qualcomm.com (10.47.97.35) 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-ORIG-GUID: D0EbXY6CgSKPSUJYZWD9pCpvWqlKk2Vp X-Proofpoint-GUID: D0EbXY6CgSKPSUJYZWD9pCpvWqlKk2Vp 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=2023-04-10_16,2023-04-06_03,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 bulkscore=0 priorityscore=1501 impostorscore=0 mlxlogscore=999 adultscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 phishscore=0 spamscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304100204 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.