From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Lukasz Luba <lukasz.luba@arm.com>
Cc: rjw@rjwysocki.net, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, linux-doc@vger.kernel.org,
devicetree@vger.kernel.org, robh+dt@kernel.org, amitk@kernel.org,
corbet@lwn.net, Dietmar.Eggemann@arm.com, qperret@google.com,
dianders@chromium.org, mka@chromium.org, rnayak@codeaurora.org
Subject: Re: [PATCH v2 0/3] Clarify abstract scale usage for power values in Energy Model, EAS and IPA
Date: Thu, 15 Oct 2020 12:21:55 +0200 [thread overview]
Message-ID: <00ceec64-3273-bb4a-6f38-22de8d877ab5@linaro.org> (raw)
In-Reply-To: <3e3dd42c-48ac-7267-45c5-ca88205611bd@arm.com>
On 15/10/2020 11:00, Lukasz Luba wrote:
[ ... ]
>> There is the SCMI and the DT. Because there are two sources where it is
>> impossible to know if they are using the same units, we are stuck to
>> ensure a consistency for the kernel.
>>
>> The platform should use:
>> - the SCMI only (scaled or real)
>> - the DT only (real)
>> [ - the firmware file only (scaled or real) ]
>>
>
> Do you mean by SCMI - registration using em_dev_register_perf_domain() ?
It was high level description, but yes, I guess it is the case.
>> As it is not possible to know if they are scaled or real, there is no
>> choice except making them mutually exclusive.
>
> So you propose a bit more restriction in registration EM, to not get
> lost in the future. I also have these doubts. Let's consider it and
> maybe agree.
>
> I've recommended Qcom to use em_dev_register_perf_domain() when they
> have this obfuscated power values. Then any developer in the future
> who wants to add EM for a new device on that platform, should use the
> em_dev_register_perf_domain().
>
> In this case the flag in EM that you have proposed makes sense.
> We probably need an argument 'bool abstract_scale' in the
> em_dev_register_perf_domain(..., bool abstract_scale)
> as a source of information.
I was suggesting to add a flag to the em_perf_domain structure giving
the source of the power numbers.
So if the IPA is having the 'sustainable-power' set in DT but the
em_perf_domain is flagged with power number coming from SCMI, then they
will be incompatible, the thermal zone will fail to register.
> We would allow to co-exist em_dev_register_perf_domain(..., false)
> with dev_pm_opp_of_register_em() EM devices.
>
> Is it make sense?
Well, it does not change my opinion. We should assume the energy model
is always milliwatts. If the SoC vendors find a way to get around with
bogoWatts, then good to them and up to them to deal with in the future.
--
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next prev parent reply other threads:[~2020-10-15 10:22 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 11:44 [PATCH v2 0/3] Clarify abstract scale usage for power values in Energy Model, EAS and IPA Lukasz Luba
2020-10-02 11:44 ` [PATCH v2 1/3] docs: Clarify abstract scale usage for power values in Energy Model Lukasz Luba
2020-10-02 11:44 ` [PATCH v2 2/3] PM / EM: update the comments related to power scale Lukasz Luba
2020-10-02 11:44 ` [PATCH v2 3/3] dt-bindings: thermal: update sustainable-power with abstract scale Lukasz Luba
2020-10-02 14:31 ` Doug Anderson
2020-10-02 15:12 ` Lukasz Luba
2020-10-02 15:47 ` Doug Anderson
2020-10-02 16:40 ` Lukasz Luba
2020-10-02 17:39 ` Doug Anderson
2020-10-06 22:24 ` Rob Herring
2020-10-07 1:17 ` Doug Anderson
2020-10-07 13:26 ` Rob Herring
2020-10-07 21:40 ` Doug Anderson
2020-10-08 14:20 ` Lukasz Luba
2020-10-08 16:41 ` Doug Anderson
2020-10-07 9:03 ` Lukasz Luba
2020-10-05 13:58 ` Rob Herring
2020-10-05 16:14 ` Lukasz Luba
2020-10-09 9:16 ` [PATCH v2 0/3] Clarify abstract scale usage for power values in Energy Model, EAS and IPA Lukasz Luba
2020-10-14 8:22 ` Daniel Lezcano
2020-10-14 9:08 ` Lukasz Luba
2020-10-14 11:23 ` Daniel Lezcano
2020-10-14 15:24 ` Lukasz Luba
2020-10-14 17:10 ` Daniel Lezcano
2020-10-15 9:00 ` Lukasz Luba
2020-10-15 10:21 ` Daniel Lezcano [this message]
2020-10-15 13:40 ` Rafael J. Wysocki
2020-10-15 15:04 ` Quentin Perret
2020-10-16 11:48 ` Daniel Lezcano
2020-10-16 12:18 ` Quentin Perret
2020-10-16 12:50 ` Daniel Lezcano
2020-10-16 13:09 ` Quentin Perret
2020-10-16 14:36 ` Doug Anderson
2020-10-16 15:55 ` Quentin Perret
2020-10-16 14:42 ` Lukasz Luba
2020-10-16 16:02 ` Quentin Perret
2020-10-19 10:35 ` Lukasz Luba
2020-10-15 13:33 ` Rafael J. Wysocki
2020-10-15 13:39 ` Daniel Lezcano
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