From nobody Tue Jun 23 13:20:43 2026 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 2E4FBC433F5 for ; Fri, 4 Mar 2022 08:24:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233317AbiCDIY6 (ORCPT ); Fri, 4 Mar 2022 03:24:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233287AbiCDIYx (ORCPT ); Fri, 4 Mar 2022 03:24:53 -0500 Received: from alexa-out-sd-02.qualcomm.com (alexa-out-sd-02.qualcomm.com [199.106.114.39]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A28318BA5F; Fri, 4 Mar 2022 00:24:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1646382245; x=1677918245; h=from:to:cc:subject:date:message-id:mime-version; bh=QnY+De45lh3dkdn8KOBNLbFmgPbGNeJtHbQNMrb6RTA=; b=IJDB1dus+vTAGMkRK12hoQBcN7YWLoUrO8dqq3TUtQgAquR7pdyUU4Km UTO2j6xsfqMuh1igH8eH0l1135Pfr0cLpCTseORKDMi4Q0kAWT2vNZGxB LMDoXbltCcEK8/zcc5zo4JiMqr6TGNWlFnHPDw7mteKP01U3SkqpVIsfv 8=; Received: from unknown (HELO ironmsg01-sd.qualcomm.com) ([10.53.140.141]) by alexa-out-sd-02.qualcomm.com with ESMTP; 04 Mar 2022 00:24:05 -0800 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg01-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Mar 2022 00:24:04 -0800 Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.15; Fri, 4 Mar 2022 00:24:04 -0800 Received: from hu-jinlmao-lv.qualcomm.com (10.49.16.6) 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 15.2.986.15; Fri, 4 Mar 2022 00:24:03 -0800 From: Mao Jinlong To: Mathieu Poirier , Suzuki K Poulose , Mike Leach , Leo Yan , Alexander Shishkin CC: Mao Jinlong , , , , , Tingwei Zhang , Yuanfang Zhang , Tao Zhang , Hao Zhang Subject: [PATCH v2] coresight: core: Fix coresight device probe failure issue Date: Fri, 4 Mar 2022 00:23:50 -0800 Message-ID: <20220304082350.30069-1-quic_jinlmao@quicinc.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01a.na.qualcomm.com (10.47.209.196) To nalasex01a.na.qualcomm.com (10.47.209.196) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" It is possibe that probe failure issue happens when the device and its child_device's probe happens at the same time. In coresight_make_links, has_conns_grp is true for parent, but has_conns_grp is false for child device as has_conns_grp is set to true in coresight_create_conns_sysfs_group. The probe of parent device will fail at this condition. Add has_conns_grp check for child device before make the links and make the process from device_register to connection_create be atomic to avoid this probe failure issue. Suggested-by: Suzuki K Poulose Suggested-by: Mike Leach Signed-off-by: Mao Jinlong --- drivers/hwtracing/coresight/coresight-core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtraci= ng/coresight/coresight-core.c index 88653d1c06a4..b3e3bc59c09b 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -1382,7 +1382,7 @@ static int coresight_fixup_device_conns(struct coresi= ght_device *csdev) continue; conn->child_dev =3D coresight_find_csdev_by_fwnode(conn->child_fwnode); - if (conn->child_dev) { + if (conn->child_dev && conn->child_dev->has_conns_grp) { ret =3D coresight_make_links(csdev, conn, conn->child_dev); if (ret) @@ -1594,7 +1594,8 @@ struct coresight_device *coresight_register(struct co= resight_desc *desc) refcnts =3D kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL); if (!refcnts) { ret =3D -ENOMEM; - goto err_free_csdev; + kfree(csdev); + goto err_out; } =20 csdev->refcnt =3D refcnts; @@ -1619,8 +1620,10 @@ struct coresight_device *coresight_register(struct c= oresight_desc *desc) csdev->dev.fwnode =3D fwnode_handle_get(dev_fwnode(desc->dev)); dev_set_name(&csdev->dev, "%s", desc->name); =20 + mutex_lock(&coresight_mutex); ret =3D device_register(&csdev->dev); if (ret) { + mutex_unlock(&coresight_mutex); put_device(&csdev->dev); /* * All resources are free'd explicitly via @@ -1634,6 +1637,7 @@ struct coresight_device *coresight_register(struct co= resight_desc *desc) ret =3D etm_perf_add_symlink_sink(csdev); =20 if (ret) { + mutex_unlock(&coresight_mutex); device_unregister(&csdev->dev); /* * As with the above, all resources are free'd @@ -1645,8 +1649,6 @@ struct coresight_device *coresight_register(struct co= resight_desc *desc) } } =20 - mutex_lock(&coresight_mutex); - ret =3D coresight_create_conns_sysfs_group(csdev); if (!ret) ret =3D coresight_fixup_device_conns(csdev); @@ -1663,8 +1665,6 @@ struct coresight_device *coresight_register(struct co= resight_desc *desc) =20 return csdev; =20 -err_free_csdev: - kfree(csdev); err_out: /* Cleanup the connection information */ coresight_release_platform_data(NULL, desc->pdata); --=20 2.17.1