From patchwork Wed Feb 22 11:43:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Pernamitta X-Patchwork-Id: 655778 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 08A20C636D6 for ; Wed, 22 Feb 2023 11:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231797AbjBVLov (ORCPT ); Wed, 22 Feb 2023 06:44:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231618AbjBVLor (ORCPT ); Wed, 22 Feb 2023 06:44:47 -0500 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 051E725E34; Wed, 22 Feb 2023 03:44:46 -0800 (PST) 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 31MBEI2H011797; Wed, 22 Feb 2023 11:43:59 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id; s=qcppdkim1; bh=6Jb/HhgDkTHs53HEkoSPSvpG8IYEg7M1HjhELiPXmTU=; b=cx+ntzwnNGXtaZmwHvYrvuFGr7YyPkdxZEXeqt0KNuhBs6F5pIoHxCZkddy7jb+Rljsi kj6Kb8WJzAUKnKd6GAjFpvp4lbHYlT0l6FiWPq5NugaoJDukob8ElI5HiTRdSyVwEvbA nmN3u41AB86djjQweJ7d+/c/iLu+2WAydbfT5KeOTJRnlJ+itKiExnZIYNbByG0pwPue MybDXPJ7q5D8VJNILzL4UAYA2VuOanK5UlzsNssL9JE0XPOE9JPHsr7Qcp8dJhKW2VZ1 pwXt7vPRjdMOy98NWjjWLi/HynvOWKh4GEV4iYSAq4wOwdLN9H2eGr0E6VTVkmRnRu1P SA== Received: from apblrppmta02.qualcomm.com (blr-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.18.19]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3nvn8rc94x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 22 Feb 2023 11:43:58 +0000 Received: from pps.filterd (APBLRPPMTA02.qualcomm.com [127.0.0.1]) by APBLRPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTP id 31MBhtDO018205; Wed, 22 Feb 2023 11:43:55 GMT Received: from pps.reinject (localhost [127.0.0.1]) by APBLRPPMTA02.qualcomm.com (PPS) with ESMTP id 3ntqrkwas7-1; Wed, 22 Feb 2023 11:43:55 +0000 Received: from APBLRPPMTA02.qualcomm.com (APBLRPPMTA02.qualcomm.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 31MBhsTG018200; Wed, 22 Feb 2023 11:43:54 GMT Received: from hu-sgudaval-hyd.qualcomm.com (hu-vpernami-hyd.qualcomm.com [10.213.107.240]) by APBLRPPMTA02.qualcomm.com (PPS) with ESMTP id 31MBhsQp018199; Wed, 22 Feb 2023 11:43:54 +0000 Received: by hu-sgudaval-hyd.qualcomm.com (Postfix, from userid 2370923) id DB3541570; Wed, 22 Feb 2023 17:13:53 +0530 (+0530) From: Vivek Pernamitta To: mhi@lists.linux.dev Cc: quic_qianyu@quicinc.com, manivannan.sadhasivam@linaro.org, quic_vbadigan@quicinc.com, quic_krichai@quicinc.com, quic_skananth@quicinc.com, Vivek Pernamitta , Manivannan Sadhasivam , Alex Elder , Greg Kroah-Hartman , Hemant Kumar , Jeffrey Hugo , Paul Davey , linux-arm-msm@vger.kernel.org (open list:MHI BUS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v4] bus: mhi: host: Avoid ringing EV DB if there is no elements to process Date: Wed, 22 Feb 2023 17:13:49 +0530 Message-Id: <1677066231-14931-1-git-send-email-quic_vpernami@quicinc.com> X-Mailer: git-send-email 2.7.4 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: tWF58_1seZiuV5KdiCYtrfrZ7Niq6o7B X-Proofpoint-ORIG-GUID: tWF58_1seZiuV5KdiCYtrfrZ7Niq6o7B X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.170.22 definitions=2023-02-22_05,2023-02-22_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 phishscore=0 mlxlogscore=696 bulkscore=0 adultscore=0 mlxscore=0 clxscore=1015 impostorscore=0 spamscore=0 priorityscore=1501 lowpriorityscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302220103 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Avoid ringing Event DB if there is no elements to process. As mhi_poll function can be called by mhi client drivers which will call process_event, which will ring DB even if there no ring elements to process. Signed-off-by: Vivek Pernamitta --- changes since v3: - Updating commit text for multiple versions of patches. changes since v2: - Updated comments in code. changes since v1: - Add an check to avoid ringing EV DB in mhi_process_ctrl_ev_ring(). --- drivers/bus/mhi/host/main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c index df0fbfe..1bbdb75 100644 --- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -961,7 +961,9 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl, } read_lock_bh(&mhi_cntrl->pm_lock); - if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) + + /* Ring EV DB only if there is any pending element to process */ + if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)) && count) mhi_ring_er_db(mhi_event); read_unlock_bh(&mhi_cntrl->pm_lock); @@ -1031,7 +1033,9 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl, count++; } read_lock_bh(&mhi_cntrl->pm_lock); - if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl))) + + /* Ring EV DB only if there is any pending element to process */ + if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)) && count) mhi_ring_er_db(mhi_event); read_unlock_bh(&mhi_cntrl->pm_lock);