From patchwork Fri Nov 17 00:39:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baochen Qiang X-Patchwork-Id: 13458313 X-Patchwork-Delegate: kvalo@adurom.com 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 33821C197A0 for ; Fri, 17 Nov 2023 00:39:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229783AbjKQAjo (ORCPT ); Thu, 16 Nov 2023 19:39:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbjKQAjo (ORCPT ); Thu, 16 Nov 2023 19:39:44 -0500 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC913129 for ; Thu, 16 Nov 2023 16:39:40 -0800 (PST) Received: from pps.filterd (m0279864.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3AGNNxuR005980; Fri, 17 Nov 2023 00:39:33 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=txnuiTa0Z12sp0K/RsZveJF3kG7JhsDHiWnQnhf6CK8=; b=YNa3Jeo1mTJCNUPwC0S+Rd3VEUHsSX8ksinIUznU6Dvuc11IdmtAKLNvN3yljyUhW86s k0b8xgl5McHNmGr7rvQZsNo5vs4XJsavu6ilUzv/K+CfzVCN9thjln3vVfFwYgfINl+k 7jPhP9v/7+rWQz6QW5Ws05tVMqTVOD0CUJXOGTRFAKZIZTUonuCw5lH6lhxQyQtd2Ajg Pp6p5iNIgc5Ng2O0o406b/G83ohDDQq3fZxnJwM9HHdYirbH/SlXLPKzTMgTolIJNXkB 8b9kMYzY4NF2Wtj4bKkp2WdHPZvZIYLQPc1qIDQq1rnjidCopvzNEuIWhPQ8nmW1yb1s Rg== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3udt8bre9r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 17 Nov 2023 00:39:32 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 3AH0dW3d029432 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 17 Nov 2023 00:39:32 GMT Received: from bqiang-SFF.qca.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 15.2.1118.39; Thu, 16 Nov 2023 16:39:31 -0800 From: Baochen Qiang To: CC: Subject: [PATCH] wifi: ath11k: fix race due to setting ATH11K_FLAG_EXT_IRQ_ENABLED too early Date: Fri, 17 Nov 2023 08:39:19 +0800 Message-ID: <20231117003919.26218-1-quic_bqiang@quicinc.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) 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-ORIG-GUID: 6mfAgX1eoRDIgDx7wLscMM9JYC4mPZ8J X-Proofpoint-GUID: 6mfAgX1eoRDIgDx7wLscMM9JYC4mPZ8J X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-16_24,2023-11-16_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 impostorscore=0 priorityscore=1501 suspectscore=0 mlxscore=0 mlxlogscore=758 adultscore=0 bulkscore=0 malwarescore=0 spamscore=0 phishscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311170002 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org We are seeing below error randomly in the case where only one MSI vector is configured: kernel: ath11k_pci 0000:03:00.0: wmi command 16387 timeout The reason is, currently, in ath11k_pcic_ext_irq_enable(), ATH11K_FLAG_EXT_IRQ_ENABLED is set before NAPI is enabled. This results in a race condition: after ATH11K_FLAG_EXT_IRQ_ENABLED is set but before NAPI enabled, CE interrupt breaks in. Since IRQ is shared by CE and data path, ath11k_pcic_ext_interrupt_handler() is also called where we call disable_irq_nosync() to disable IRQ. Then napi_schedule() is called but it does nothing because NAPI is not enabled at that time, meaning ath11k_pcic_ext_grp_napi_poll() will never run, so we have no chance to call enable_irq() to enable IRQ back. Finally we get above error. Fix it by setting ATH11K_FLAG_EXT_IRQ_ENABLED after all NAPI and IRQ work are done. With the fix, we are sure that by the time ATH11K_FLAG_EXT_IRQ_ENABLED is set, NAPI is enabled. Note that the fix above also introduce some side effects: if ath11k_pcic_ext_interrupt_handler() breaks in after NAPI enabled but before ATH11K_FLAG_EXT_IRQ_ENABLED set, nothing will be done by the handler this time, the work will be postponed till the next time the IRQ fires. Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23 Signed-off-by: Baochen Qiang Acked-by: Jeff Johnson --- drivers/net/wireless/ath/ath11k/pcic.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) base-commit: 9a36440d929d134c56030a8492405708a143f580 diff --git a/drivers/net/wireless/ath/ath11k/pcic.c b/drivers/net/wireless/ath/ath11k/pcic.c index 16d1e332193f..e602d4130105 100644 --- a/drivers/net/wireless/ath/ath11k/pcic.c +++ b/drivers/net/wireless/ath/ath11k/pcic.c @@ -460,8 +460,6 @@ void ath11k_pcic_ext_irq_enable(struct ath11k_base *ab) { int i; - set_bit(ATH11K_FLAG_EXT_IRQ_ENABLED, &ab->dev_flags); - for (i = 0; i < ATH11K_EXT_IRQ_GRP_NUM_MAX; i++) { struct ath11k_ext_irq_grp *irq_grp = &ab->ext_irq_grp[i]; @@ -471,6 +469,8 @@ void ath11k_pcic_ext_irq_enable(struct ath11k_base *ab) } ath11k_pcic_ext_grp_enable(irq_grp); } + + set_bit(ATH11K_FLAG_EXT_IRQ_ENABLED, &ab->dev_flags); } EXPORT_SYMBOL(ath11k_pcic_ext_irq_enable);