From patchwork Mon Dec 11 06:42:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qiang Yu X-Patchwork-Id: 13486712 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="bD5hylfl" Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62248C3; Sun, 10 Dec 2023 22:43:10 -0800 (PST) Received: from pps.filterd (m0279869.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.24/8.17.1.24) with ESMTP id 3BB5anrG008038; Mon, 11 Dec 2023 06:42:59 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; s= qcppdkim1; bh=e1+zOy1qUA8HHZYc5Bz8jvBUDY2bNGJthqVjZfAWwWM=; b=bD 5hylflfZoXirBZeF7jkwfSwl0KoeG0YIy39hjF3Yzpr/g1tWmWUAOYns7+1UJRWJ Ji0AcX1dEfMCj8gmsIwfGs2hYTMM5W+leJIM8fnH3T0Lhz9lr8RBftmkL8yjwoBy IFqbl/xXh/MKp2GTtbU3HgNHhEKGT5OMRddJyoHvYh7rSQ2e133YTrcBLFIKXf8c /DdrbXoZDuX0ZIYOUoI1t3D+mreZjipKtjl5AANBE2hTt2J0RVrB59jjQoOi7Wty cQUXw27bS2Hn8zqJ1WIKtqCLfYRvWR4TiWW0Z15Tne2Kj9Gu27ghoN4tXbzwe07b SB2f4Q27end1v8wLS3MA== Received: from aptaippmta01.qualcomm.com (tpe-colo-wan-fw-bordernet.qualcomm.com [103.229.16.4]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3uvnyvadhq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 11 Dec 2023 06:42:58 +0000 (GMT) Received: from pps.filterd (APTAIPPMTA01.qualcomm.com [127.0.0.1]) by APTAIPPMTA01.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTP id 3BB6gt7s030880; Mon, 11 Dec 2023 06:42:56 GMT Received: from pps.reinject (localhost [127.0.0.1]) by APTAIPPMTA01.qualcomm.com (PPS) with ESMTP id 3uvhak95cv-1; Mon, 11 Dec 2023 06:42:56 +0000 Received: from APTAIPPMTA01.qualcomm.com (APTAIPPMTA01.qualcomm.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3BB6gtSu030875; Mon, 11 Dec 2023 06:42:56 GMT Received: from cbsp-sh-gv.qualcomm.com (CBSP-SH-gv.ap.qualcomm.com [10.231.249.68]) by APTAIPPMTA01.qualcomm.com (PPS) with ESMTP id 3BB6gt3O030883; Mon, 11 Dec 2023 06:42:56 +0000 Received: by cbsp-sh-gv.qualcomm.com (Postfix, from userid 4098150) id 3466B55E9; Mon, 11 Dec 2023 14:42:55 +0800 (CST) From: Qiang Yu To: mani@kernel.org, quic_jhugo@quicinc.com Cc: mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, quic_cang@quicinc.com, quic_mrana@quicinc.com, Qiang Yu Subject: [PATCH v5 2/2] bus: mhi: host: Drop chan lock before queuing buffers Date: Mon, 11 Dec 2023 14:42:52 +0800 Message-Id: <1702276972-41296-3-git-send-email-quic_qianyu@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1702276972-41296-1-git-send-email-quic_qianyu@quicinc.com> References: <1702276972-41296-1-git-send-email-quic_qianyu@quicinc.com> X-QCInternal: smtphost X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: 8Df1Yo5-Hlz7hPdjP3ssHD4aAAr05k0g X-Proofpoint-ORIG-GUID: 8Df1Yo5-Hlz7hPdjP3ssHD4aAAr05k0g X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-09_02,2023-12-07_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 mlxlogscore=639 suspectscore=0 spamscore=0 bulkscore=0 clxscore=1015 phishscore=0 adultscore=0 mlxscore=0 lowpriorityscore=0 malwarescore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2311290000 definitions=main-2312110054 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Ensure read and write locks for the channel are not taken in succession by dropping the read lock from parse_xfer_event() such that a callback given to client can potentially queue buffers and acquire the write lock in that process. Any queueing of buffers should be done without channel read lock acquired as it can result in multiple locks and a soft lockup. Signed-off-by: Qiang Yu Reviewed-by: Jeffrey Hugo Tested-by: Jeffrey Hugo Reviewed-by: Manivannan Sadhasivam --- drivers/bus/mhi/host/main.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c index 32021fe..25f98d6 100644 --- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -642,6 +642,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, mhi_del_ring_element(mhi_cntrl, tre_ring); local_rp = tre_ring->rp; + read_unlock_bh(&mhi_chan->lock); + /* notify client */ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result); @@ -667,6 +669,8 @@ static int parse_xfer_event(struct mhi_controller *mhi_cntrl, kfree(buf_info->cb_buf); } } + + read_lock_bh(&mhi_chan->lock); } break; } /* CC_EOT */