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 B566D2882A9; Fri, 19 Dec 2025 10:42:44 +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=1766140966; cv=none; b=O566JSuVhgLWjDz4OJ4fjRABtamhr/lx7avGfuWyRQTSsMUNr74MA6/nF3qjPo4RR1/ZNnRCy0wzRBxEH/VtF2Pa6RoKmeDzGcY9X9FismXPrCFymTQPYUdK4t4qYSVV39Y6ep3lw+Tpsuq51QBsOYvyM/xeChbJ3+LOtXauyQQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766140966; c=relaxed/simple; bh=j80u/3tGqchMI0uX25fhG4G01nqVVbFk3nPN3+udHKc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NLoez0pvlDlf6BpQ8RAdBckv8Wnj5Q3USbn6vD/j12ZwFsFze30DpT6m8srSrNQUsoagEO2NkOlrCnG5Ph857xDBC5IKRkgcbORGnll1VH5JYLyUxwGJbsndTQEUvGqMMj0x0WzssqBATQcLWAxWI45sUCGcXVKJbUMpRTmS8p0= 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; 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 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 2DF2C106F; Fri, 19 Dec 2025 02:42:37 -0800 (PST) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DE2FB3F5CA; Fri, 19 Dec 2025 02:42:43 -0800 (PST) Date: Fri, 19 Dec 2025 10:42:41 +0000 From: Leo Yan To: yuanfang zhang Cc: Suzuki K Poulose , Mike Leach , James Clark , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Mathieu Poirier , Leo Yan , Alexander Shishkin , Bjorn Andersson , Konrad Dybcio , kernel@oss.qualcomm.com, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, maulik.shah@oss.qualcomm.com, Jie Gan Subject: Re: [PATCH v2 00/12] coresight: Add CPU cluster funnel/replicator/tmc support Message-ID: <20251219104241.GB9788@e132581.arm.com> References: <20251218-cpu_cluster_component_pm-v2-0-2335a6ae62a0@oss.qualcomm.com> <20251218104027.GA1790402@e132581.arm.com> <927f15d5-da2a-4282-b80f-c1c7563a4367@oss.qualcomm.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <927f15d5-da2a-4282-b80f-c1c7563a4367@oss.qualcomm.com> On Fri, Dec 19, 2025 at 09:50:18AM +0800, yuanfang zhang wrote: [...] > It is due to the particular characteristics of the CPU cluster power domain. > Runtime PM for CPU devices works little different, it is mostly used to manage hierarchical > CPU topology (PSCI OSI mode) to talk with genpd framework to manage the last CPU handling in > cluster. > It doesn’t really send IPI to wakeup CPU device (It don’t have .power_on/.power_off) callback > implemented which gets invoked from .runtime_resume callback. This behavior is aligned with > the upstream Kernel. Just for easier understanding, let me give an example: funnel0: funnel@10000000 { compatible = "arm,coresight-dynamic-funnel", "arm,primecell"; reg = <0x10000000 0x1000>; clocks = <&rpmcc RPM_SMD_QDSS_CLK>, <&rpmcc RPM_SMD_QDSS_A_CLK>; clock-names = "apb_pclk", "atclk"; power-domains = <&cluster0_pd>; } If funnel0 is bound to cluster's power domain, kernel's genPD will automatically enable cluster power domain before access registers. My understanding is your driver or firmware fails to turn on a cluster power domain without waking up a CPU (and without sending IPI). It is not a kernel issue or limitation, and no any incorrect in PSCI OSI. As Suzuki said, you might directly reply Sudeep's questions. We would confirm if any flaw in common code. > > P.s., currently you can use "taskset" as a temporary solution without > > any code change, something like: > > > > taskset -c 0 echo 1 > /sys/bus/coresight/devices/etm0/enable_source > > This can address the runtime issue, but it does not resolve the problem during the probe phase. Indeed. If you insmod mode, you might can temporarily disable idle states? exec 3<> /dev/cpu_dma_latency; echo 0 >&3 insmod exec 3<>- Thanks, Leo