From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Sudeep Holla <sudeep.holla@arm.com>,
yuanfang zhang <yuanfang.zhang@oss.qualcomm.com>
Cc: Mike Leach <mike.leach@linaro.org>,
James Clark <james.clark@linaro.org>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
Leo Yan <leo.yan@linux.dev>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Bjorn Andersson <andersson@kernel.org>,
Konrad Dybcio <konradybcio@kernel.org>,
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 <jie.gan@oss.qualcomm.com>
Subject: Re: [PATCH v2 00/12] coresight: Add CPU cluster funnel/replicator/tmc support
Date: Fri, 19 Dec 2025 10:28:01 +0000 [thread overview]
Message-ID: <e9df1140-989f-46e3-8edc-2013e520bfed@arm.com> (raw)
In-Reply-To: <20251219-hysterical-sparkling-meerkat-59c5eb@sudeepholla>
On 19/12/2025 10:21, Sudeep Holla wrote:
> On Fri, Dec 19, 2025 at 10:13:14AM +0800, yuanfang zhang wrote:
>>
>>
>> On 12/18/2025 7:33 PM, Sudeep Holla wrote:
>>> On Thu, Dec 18, 2025 at 12:09:40AM -0800, Yuanfang Zhang wrote:
>>>> This patch series adds support for CoreSight components local to CPU clusters,
>>>> including funnel, replicator, and TMC, which reside within CPU cluster power
>>>> domains. These components require special handling due to power domain
>>>> constraints.
>>>>
>>>
>>> Could you clarify why PSCI-based power domains associated with clusters in
>>> domain-idle-states cannot address these requirements, given that PSCI CPU-idle
>>> OSI mode was originally intended to support them? My understanding of this
>>> patch series is that OSI mode is unable to do so, which, if accurate, appears
>>> to be a flaw that should be corrected.
>>
>> 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 hierarchicalCPU topology (PSCI OSI mode) to talk with genpd
>> framework to manage the last CPU handling in cluster.
>
> That is indeed the intended design. Could you clarify which specific
> characteristics differentiate it here?
>
>> 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.
>>
>
> I am quite lost here. Why is it necessary to wake up the CPU? If I understand
> correctly, all of this complexity is meant to ensure that the cluster power
> domain is enabled before any of the funnel registers are accessed. Is that
> correct?
>
> If so, and if the cluster domains are already defined as the power domains for
> these funnel devices, then they should be requested to power on automatically
> before any register access occurs. Is that not the case?
>
> What am I missing in this reasoning?
Exactly, this is what I am too. But then you get the "pre-formated
standard response" without answering our questions.
Suzuki
prev parent reply other threads:[~2025-12-19 10:28 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-18 8:09 [PATCH v2 00/12] coresight: Add CPU cluster funnel/replicator/tmc support Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 01/12] dt-bindings: arm: coresight: Add 'qcom,cpu-bound-components' property Yuanfang Zhang
2025-12-18 11:37 ` Sudeep Holla
2025-12-18 8:09 ` [PATCH v2 02/12] coresight-funnel: Support CPU cluster funnel initialization Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 03/12] coresight-funnel: Defer probe when associated CPUs are offline Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 04/12] coresight-replicator: Support CPU cluster replicator initialization Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 05/12] coresight-replicator: Defer probe when associated CPUs are offline Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 06/12] coresight-replicator: Update management interface for CPU-bound devices Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 07/12] coresight-tmc: Support probe and initialization for CPU cluster TMCs Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 08/12] coresight-tmc-etf: Refactor enable function for CPU cluster ETF support Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 09/12] coresight-tmc: Update management interface for CPU-bound TMCs Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 10/12] coresight-tmc: Defer probe when associated CPUs are offline Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 11/12] coresight: Pass trace mode to link enable callback Yuanfang Zhang
2025-12-18 8:09 ` [PATCH v2 12/12] arm64: dts: qcom: hamoa: Add CoreSight nodes for APSS debug block yuanfang Zhang
2025-12-18 9:32 ` [PATCH v2 00/12] coresight: Add CPU cluster funnel/replicator/tmc support Suzuki K Poulose
2025-12-18 16:18 ` yuanfang zhang
2025-12-18 17:04 ` Suzuki K Poulose
2025-12-19 10:06 ` Sudeep Holla
2025-12-18 10:40 ` Leo Yan
2025-12-19 1:50 ` yuanfang zhang
2025-12-19 10:42 ` Leo Yan
2025-12-18 11:33 ` Sudeep Holla
2025-12-19 2:13 ` yuanfang zhang
2025-12-19 10:21 ` Sudeep Holla
2025-12-19 10:28 ` Suzuki K Poulose [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=e9df1140-989f-46e3-8edc-2013e520bfed@arm.com \
--to=suzuki.poulose@arm.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=andersson@kernel.org \
--cc=conor+dt@kernel.org \
--cc=coresight@lists.linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=james.clark@linaro.org \
--cc=jie.gan@oss.qualcomm.com \
--cc=kernel@oss.qualcomm.com \
--cc=konradybcio@kernel.org \
--cc=krzk+dt@kernel.org \
--cc=leo.yan@linux.dev \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.poirier@linaro.org \
--cc=maulik.shah@oss.qualcomm.com \
--cc=mike.leach@linaro.org \
--cc=robh@kernel.org \
--cc=sudeep.holla@arm.com \
--cc=yuanfang.zhang@oss.qualcomm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox