From patchwork Fri Apr 7 22:40:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 13205447 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 CC39BC76196 for ; Fri, 7 Apr 2023 22:40:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229745AbjDGWkv (ORCPT ); Fri, 7 Apr 2023 18:40:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230383AbjDGWku (ORCPT ); Fri, 7 Apr 2023 18:40:50 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59F18D332; Fri, 7 Apr 2023 15:40:45 -0700 (PDT) Received: from pps.filterd (m0279865.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 337Med0v004586; Fri, 7 Apr 2023 22:40:39 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-type; s=qcppdkim1; bh=/koRs7Aex0OQKVto47rpNAga0+XbJLWelLS+sFsiZ2s=; b=l8Aeds8xpHOBKFQE7vPl54XGR0FM0/7tS9DPEh7Hs+QiDPQD0tjBgyDZcPpCTWJ1A+Bj CEWrZDgn8exaGGcnvji6TFBfdH/XcideYoranXV86SJ0GFeOHqEOLbrX7mymkTfnetQO XNhNHanRghFhkEyhSA2wlo9pkUgC8WcqSgsYjEMInsXqdla8iPe0fXb43z+BI0Z5n96X 2nJ9DVL9p4IpyowMRKz5eXsgLodfnczlQSj18Jkfhd1P+wYiufc58ROCYAGWqtN1qeDb 6+JGMIYK/u84x59UI5Q7hZyUpJ1jc4YpUKrXISnmRoL5QY2vFZcS/gneljMOvN3QXRkG QA== Received: from nalasppmta05.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3ptcrn20dt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 07 Apr 2023 22:40:38 +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 337MecBm019237 (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 15:40:37 -0700 From: Wesley Cheng To: , CC: , , , , Wesley Cheng Subject: [PATCH v2 0/3] Avoid having pending end transfers on soft disconnect Date: Fri, 7 Apr 2023 15:40:22 -0700 Message-ID: <20230407224025.22315-1-quic_wcheng@quicinc.com> X-Mailer: git-send-email 2.17.1 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-ORIG-GUID: BjSowptd-l7C-WKGHStm96bf_bkEAGiv X-Proofpoint-GUID: BjSowptd-l7C-WKGHStm96bf_bkEAGiv 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 lowpriorityscore=0 malwarescore=0 bulkscore=0 mlxscore=0 clxscore=1015 impostorscore=0 priorityscore=1501 phishscore=0 spamscore=0 mlxlogscore=644 suspectscore=0 adultscore=0 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 In case there is a host which takes time to complete a SETUP transaction, during the soft disconnect sequence multiple DWC3 EPs will have their DWC3_EP_DELAY_STOP flag set w/o issuing the end transfer command. Once the controller halt sequence occurs, the soft disconnect is successful, and the subsequent soft connect will attempt to flush the pending end transfers. Soft disconnect sequence: 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 Soft connect bug: BUG: spinlock already unlocked on CPU spin_bug+0x0 dwc3_remove_requests+0x278 dwc3_ep0_out_start+0xb0 __dwc3_gadget_start+0x25c The bug occurs due to the flush of the pending end transfers, as the gadget start routine is not held with a spinlock. However, if the DWC3_EP_DELAY_STOP is set, it will call the giveback API, which attempts to unlock the dwc->lock. Ideally, the DWC3 gadget should not have pending end transfers on a soft connect, so fix this by: 1. 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. 2. Do not call gadget stop until the poll for controller halt is completed. DEVTEN is cleared as part of gadget stop, so the intention to allow ep0 events to continue while waiting for controller halt is not happening. Wesley Cheng (3): usb: dwc3: gadget: Refactor EP0 forced stall/restart into a separate API usb: dwc3: gadget: Stall and restart EP0 if host is unresponsive usb: dwc3: gadget: Execute gadget stop after halting the controller drivers/usb/dwc3/gadget.c | 101 ++++++++++++++++++++++---------------- 1 file changed, 58 insertions(+), 43 deletions(-)