From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 501933DC4D0 for ; Mon, 13 Apr 2026 14:20:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776090030; cv=none; b=PN7JALdyxAYlhTqw1yOcPlG3j50cYhPXn5aXglyXsuO9JZJIW28Aj1O9amcEUbXUh9/7jM3T9cQWwxQ+poymK7AyraQuJWsxGIxxgkNgevE0uJsc00OucX+hGpwDrPKH1pJtpq4ejlBqI42TWA2svDqfrAkGfw6kf1AZlgRs1vo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776090030; c=relaxed/simple; bh=Qwt8jUbbvMo92bDPS6T3dox0x9gyvJKy4t2N4lfA8uI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=joJHCxFsWs4GBcnm0epyEkD+rIjZilPwCKvQoVERyyspdNxGJhTO6Gy/bqADgokjN57AlaWA0dGqAaERpHL50IDD8NiyjPdPwgEq0cU79mFrRBlfF40qNnknmL8CtUkW4qg9cL8Si5ES0sS/SddhXsoMLYDY96tKxcLo1dWurwY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=ofYF9Bty; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="ofYF9Bty" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B4E66359A; Mon, 13 Apr 2026 07:20:19 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DE5AA3F641; Mon, 13 Apr 2026 07:20:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1776090025; bh=Qwt8jUbbvMo92bDPS6T3dox0x9gyvJKy4t2N4lfA8uI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ofYF9Btyz0Itq1rCHMGyxlKDCTtniuQuVyRoAFwqXJu5rQRRf02ImodpwuzoQsSzT igua5GyuTdCbfyFZqHfGwwqplT/2psbP1e5ugqpRdv3RBtBpHx+KskFTLNGs6QnQMW b43YLtXpxDRPzXeozyZkDDdw5KjmAJvw7LMnZr9w= From: Yeoreum Yun To: 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, jie.gan@oss.qualcomm.com, Yeoreum Yun Subject: [PATCH v4 9/9] coresight: etm3x: remove redundant call etm_enable_hw() with hotplug Date: Mon, 13 Apr 2026 15:20:03 +0100 Message-Id: <20260413142003.3549310-11-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260413142003.3549310-1-yeoreum.yun@arm.com> References: <20260413142003.3549310-1-yeoreum.yun@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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, etm_enable_hw() may be invoked in etm_enable_sysfs_smp_call() and then executed again in etm_starting_cpu(). To remove this redundant call, take the hotplug lock before executing etm_enable_sysfs_smp_call(). Signed-off-by: Yeoreum Yun --- .../coresight/coresight-etm3x-core.c | 24 +++++++++---------- 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c index b7e3b5eea3f9..5dc5492a1fb5 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -522,26 +522,26 @@ static int etm_enable_sysfs(struct coresight_device *csdev, struct coresight_pat struct etm_enable_arg arg = { }; int ret; + arg.drvdata = drvdata; + arg.traceid = path->trace_id; + + raw_spin_lock(&drvdata->spinlock); + arg.config = drvdata->config; + raw_spin_unlock(&drvdata->spinlock); /* * Configure the ETM only if the CPU is online. If it isn't online * hw configuration will take place on the local CPU during bring up. */ - if (cpu_online(drvdata->cpu)) { - arg.drvdata = drvdata; - arg.traceid = path->trace_id; - - raw_spin_lock(&drvdata->spinlock); - arg.config = drvdata->config; - raw_spin_unlock(&drvdata->spinlock); - + cpus_read_lock(); ret = smp_call_function_single(drvdata->cpu, etm_enable_sysfs_smp_call, &arg, 1); - if (!ret) - ret = arg.rc; - } else { + cpus_read_unlock(); + + if (!ret) + ret = arg.rc; + else ret = -ENODEV; - } if (!ret) dev_dbg(&csdev->dev, "ETM tracing enabled\n"); -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}