From patchwork Mon Apr 10 23:19:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 13206832 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 C5EE1C77B61 for ; Mon, 10 Apr 2023 23:20:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229884AbjDJXUM (ORCPT ); Mon, 10 Apr 2023 19:20:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229690AbjDJXUK (ORCPT ); Mon, 10 Apr 2023 19:20:10 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E22C1E7C; Mon, 10 Apr 2023 16:20:09 -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 33AN091l026043; 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 : mime-version : content-type; s=qcppdkim1; bh=MEIIiB7asQwxSOKBrgES6n0j3671fTTzzrR6gNjEmX4=; b=ZEEng0sBEpI5RA7fRLSfprilUBvI5YTmKrvf58eWkRqcd+CWkOL2BcfXMMNqCTqPqQ+R JE11LuhsOowNNpqHWgugxUS1orf+SOJqbOW5nEkDiiXBTGV6QKJDYObysUXS51ocuy6N tG4B7J3QEXnNqcCBECHvmdCZgkYtp9gJqRDiped+nYGDePLVIkEJIogxSKObsVj94XjS VizM5cvGJh/zC9lE/YC0H9nWorA1oMZVUFMjjoKLpuR6cZnv6XJrjXVuiQGrzhiPFUSt GeRB3uclj/PMEigz+dQNHggQXbULs1+Op1op1PDaCnFUeqzyFF2GPDyRSAk9M5Qst4hG Dw== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3pvq4dgga4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Apr 2023 23:20:06 +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 33ANK5l6029453 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Apr 2023 23:20:05 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 0/3] Avoid having pending end transfers on soft disconnect Date: Mon, 10 Apr 2023 16:19:51 -0700 Message-ID: <20230410231954.437-1-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: 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: N5xQwHQ1H46g0Ic5uF6749AumOcz5HEF X-Proofpoint-GUID: N5xQwHQ1H46g0Ic5uF6749AumOcz5HEF 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=629 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 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. Changes in v3: - Removed fixes tag in the refactor change 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(-)