From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 211DAF4198B for ; Wed, 15 Apr 2026 12:00:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UOPyBVh5wkfcpmshMahRfP5h7T0g+jp8/1ZUrdWzWmM=; b=wCsOUGKBHSIVjefAZb8+3yKzJc +x+FRfpqF0XoCJsMRH1jXOGf/NR2yuPaIhKJ+ajTd+JRWXn03/Fdmr0bmMLJDPgH3E2Pen/NNcfyb d6vW0fniUfBWpeurm6dmN0+naNjcAT2nmCmUqQy2MAXuHIziolNMi8kxyJwig8ZcXACiSppaGMTK+ s6MVUy5KfTViiX/ZZWbnBVZ6Ye7S3n298VUBk6pz0dpiJjpXSwGG78t4IVs1Fb9anMkKcMmSnNXv6 s0dHxmp8Ejg54PuuYlRDW9HJuChFQqj5rucZmTChq42HLJHG2zGM9Em+f0ooCztN807mbv1N2F4zK Lk3aY8ww==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wCyuf-000000015gX-0y3W; Wed, 15 Apr 2026 12:00:09 +0000 Received: from mx0a-0031df01.pphosted.com ([205.220.168.131]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wCyuc-000000015g7-3FV3 for linux-arm-kernel@lists.infradead.org; Wed, 15 Apr 2026 12:00:08 +0000 Received: from pps.filterd (m0279863.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 63F5xH8A2772654 for ; Wed, 15 Apr 2026 12:00:06 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= UOPyBVh5wkfcpmshMahRfP5h7T0g+jp8/1ZUrdWzWmM=; b=cEfc8eAuH+Y4A5Lg SSdtA3pec/wgHTjuNDycjo/I5MYM1Kl8bpc2ChLzm19PDSzQfm39PhgKczODgKSF miJ0XwU/Wi/f6VIjQwme+8mrRLWIfHy0gMRIsFoi3bqkIO/ddbiJZcZ5n3EJRGiI r6KvPtVgPpEY3MsD0QDbtmyF+i55n+/onCNQMEbdg0xp/QejxzMiK5wBu+d5PEBL HKjqmvzdDwI7u9oyzJABMMcInm1HOPjYJ+9Vr6pb1HZnms4WA8rkGgyFcDM+GtT8 wbgS5lZhufXJGbIozzpTnURw38clPixkUxuVr2xMBUuXY3JOOZJ1wLh9tOePd7Vu OGAx4g== Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4dj50v19c0-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Wed, 15 Apr 2026 12:00:06 +0000 (GMT) Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-35da97f6a6dso6915211a91.0 for ; Wed, 15 Apr 2026 05:00:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1776254405; x=1776859205; darn=lists.infradead.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=UOPyBVh5wkfcpmshMahRfP5h7T0g+jp8/1ZUrdWzWmM=; b=EQIs0vNe4Dc3SaH2g2pJfLxOyoEkF1uEVFXBHj2TAvGfPVC8V0AlOJ2AzzS7fcFvsU +okqTxxgUY5lt+JZ6bcjBHFPM73X7c9LXANh0ZK+n/2xl1uisrHiScfXvalqxmryoreF aWo8yc94yPykFgCknKeZrgZtioY6bRBDt6fCEnXuyPYUaiBI13Bc45Vhq7cf8PG0M5Si UsPLHyaN0TicvQCVJ9JfmdnX0hd1fQRG8e6XeAYKpI6ljKSxvAVzyTjHjhNg0MzTvsaT TLDVIWKsTqmaYp+kDJ7jW7nVuhPJNRTsNSdmIToWKIxhTXi1dTjoj4MpCZ354mQit6Gr 3ytA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776254405; x=1776859205; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=UOPyBVh5wkfcpmshMahRfP5h7T0g+jp8/1ZUrdWzWmM=; b=jWmvX+akweSIjFdXhJjbg7dYekr/HFvnLA6D7C4g97BiPtIEagNSdQ7T8IcGK1sZpw 9mFDy+/j0RbFL+QR27ryPDr5rPT+gWU9yeFHhtnsIqLmeEygQOhuFhEgRoDtZh6tixKi 9Qg3V3FHO8/LPaGxrbmlkX+E5ncD+1cpLOakHW9a9WKBTjnr8ea+pX6QbVMkwY7DMkXY zyjSQgeac0IKhutEsNHSS3qEwYXUl2MRLDFCUI0brqqNNOLf0WjN6H0H7zvvW7EmErke 10/MZ5fJltd25sL40YLGJ45VqKsJJxRbxxsr+zhUJAeasm+B5mffBm4+/uBasnktsSOI zLYw== X-Forwarded-Encrypted: i=1; AFNElJ9MCwhrMc1oMt6EbiMTtfCY8WjEp9k9JoRoPGvCXuZb+2rQ50+cqXE4UM87aSVOk3eQ5Hte8i62ByJZboAMiVlk@lists.infradead.org X-Gm-Message-State: AOJu0Yy0QcheFlNrygMT8hP1LpSh+j1NWjrk8hfQPgq4Lkm4fybV/HCp CziKmpyBFVshQZmxa6nzE7S+5++wPBeG3eVg8k7DcQsgpnl70WRu5JdsHr87OnM1qnnwLM72BH2 h3gAVKNxpQ2eaOMG7gp8MOeZrfenNfAEUgW68G4dJwuPgO9glALeYQ2vTN8cFvYO2QiEcMA+vmP y0mA== X-Gm-Gg: AeBDiet9gm4nh7ONN3B2tRPESkGA5fZERaqFDfqgcBpD1pP4M3jNZp+yTYEn2yH0LDh IeOYr6Z7u4yZJozaDLKIcxg8xIJmL3Uri9Qe/Tc81lI6HeYkRLbhYXFfKJ7yyNFkTgsC9DUwZLg 4DR73qyGIOVJ0n/YDCNKPtXb3sSR7BCR1Zuuni1iSy1/j9w79A7JvZtSrrXr3SXgRIGjGNqPHA0 S7xnt6HUL74FdP9khd/af+kfFRUchyCevhHnG0M9Cw6vK7AYInAtKiGF88Kj2jxIU0z9YX/yCGP xymkcZIzzft6P+vpZ3ePg42S5FsAartHexl5KOtOARoWz2027OQW7G2kd3+htqDE/9DKpLfuK/G 4wLqYEg+3kNzGvrJ/XAzznpiv8OtTbS23LMk1IjfGPwhCtxvpSt7SKrcrxOuT/mwPQnHyTiE/t2 huySrPg282dQ== X-Received: by 2002:a17:90b:3c85:b0:35d:a4c0:a0ac with SMTP id 98e67ed59e1d1-35e4278b922mr20254120a91.3.1776254405239; Wed, 15 Apr 2026 05:00:05 -0700 (PDT) X-Received: by 2002:a17:90b:3c85:b0:35d:a4c0:a0ac with SMTP id 98e67ed59e1d1-35e4278b922mr20254083a91.3.1776254404746; Wed, 15 Apr 2026 05:00:04 -0700 (PDT) Received: from [10.133.33.81] (tpe-colo-wan-fw-bordernet.qualcomm.com. [103.229.16.4]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-c7957eeb35csm1569622a12.12.2026.04.15.05.00.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 15 Apr 2026 05:00:04 -0700 (PDT) Message-ID: Date: Wed, 15 Apr 2026 19:59:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 5/9] coresight: etm4x: remove redundant call etm4_enable_hw() with hotplug To: Yeoreum Yun , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: suzuki.poulose@arm.com, mike.leach@arm.com, james.clark@linaro.org, alexander.shishkin@linux.intel.com, leo.yan@arm.com References: <20260413142003.3549310-1-yeoreum.yun@arm.com> <20260413142003.3549310-6-yeoreum.yun@arm.com> Content-Language: en-US From: Jie Gan In-Reply-To: <20260413142003.3549310-6-yeoreum.yun@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Proofpoint-GUID: JUvKNWz6YbOfgi_s4GkjHxd1-tK3iaXl X-Authority-Analysis: v=2.4 cv=eLMjSnp1 c=1 sm=1 tr=0 ts=69df7dc6 cx=c_pps a=UNFcQwm+pnOIJct1K4W+Mw==:117 a=nuhDOHQX5FNHPW3J6Bj6AA==:17 a=IkcTkHD0fZMA:10 a=A5OVakUREuEA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=yOCtJkima9RkubShWh1s:22 a=7CQSdrXTAAAA:8 a=EUspDBNiAAAA:8 a=vHEE0SP3H1NCSIy07DoA:9 a=QEXdDO2ut3YA:10 a=uKXjsCUrEbL0IQVhDsJ9:22 a=a-qgeE7W1pNrGK8U0ZQC:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNDE1MDExMCBTYWx0ZWRfX4kUfgdpU6/zc ytBM7jl1YS/T8NV+48zPELeW+u3nidEOjPus2aJ6DXJhKx8LODmbJuC2qPXDtUh8NTTgzjFa8gE sNrYZ1rZYaqml7Kf+nt3RjgR9YYOo+1IwfTk5lx+h7V17UGZ07h/eZbNQvpW+kB7J6htIpJYCm/ OANInteW0Hhhiwl++75wCNrxd5SUwKhundfqk5BG6kpuOruhznCXDYNse3zj7LfjslHGWvKU1L6 Lym9U+1ZuQBcCmgiVrQ0LDAeslYg+hSpyG5ky2Vc+sJeULDHtAxv3uPV43RA1Fz+AdJBLdrEDCS zXU/aA/6QtoKJiIbQRLLnm3o3YzSTrCBSqGvqHouLDnt59WvVdeTt8S6lgPSHo9aeQIhWVCe453 YtyUSf+4Ki07+m0AJSDE8EBJoBuVhmlnoWFpc2aPXBJj8RwuIhKfonVJd80KPQvS/3zaw6IRPGx ZBH1AsBjUTNR34kEPqQ== X-Proofpoint-ORIG-GUID: JUvKNWz6YbOfgi_s4GkjHxd1-tK3iaXl X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-04-14_04,2026-04-13_04,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 clxscore=1015 bulkscore=0 lowpriorityscore=0 impostorscore=0 suspectscore=0 malwarescore=0 priorityscore=1501 spamscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2604070000 definitions=main-2604150110 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260415_050006_835511_07AAE26F X-CRM114-Status: GOOD ( 19.90 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 4/13/2026 10:19 PM, Yeoreum Yun wrote: > The cpu_online_mask is set at the CPUHP_BRINGUP_CPU step. > In other words, if etm4_enable_sysfs() is called between > CPUHP_BRINGUP_CPU and CPUHP_AP_ARM_CORESIGHT_STARTING, > etm4_enable_hw() may be invoked in etm4_enable_sysfs_smp_call() > and then executed again in etm4_starting_cpu(). > > To remove this redundant call, take the hotplug lock before executing > etm4_enable_sysfs_smp_call(). > > Signed-off-by: Yeoreum Yun > --- > drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index 01099689525b..facd5a306228 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -959,8 +959,20 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa > arg.config = drvdata->config; > raw_spin_unlock(&drvdata->spinlock); > > + /* > + * Take the hotplug lock to prevent redundant calls to etm4_enable_hw(). > + * > + * The cpu_online_mask is set at the CPUHP_BRINGUP_CPU step. > + * In other words, if etm4_enable_sysfs() is called between > + * CPUHP_BRINGUP_CPU and CPUHP_AP_ARM_CORESIGHT_STARTING, > + * etm4_enable_hw() may be invoked in etm4_enable_sysfs_smp_call() > + * and then executed again in etm4_starting_cpu(). > + */ > + cpus_read_lock(); > ret = smp_call_function_single(drvdata->cpu, > etm4_enable_sysfs_smp_call, &arg, 1); > + cpus_read_unlock(); > + > if (!ret) > ret = arg.rc; > if (!ret) Reviewed-by: Jie Gan