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Message-ID: <9127808c-ab0c-83ce-9bc7-27f5daae30d1@quicinc.com>
Date: Tue, 16 Jan 2024 10:37:09 +0530
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Subject: Re: [PATCH v6 6/6] PCI: qcom: Add OPP support to scale performance
 state of power domain
Content-Language: en-US
To: Bjorn Helgaas <helgaas@kernel.org>
CC: Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio
	<konrad.dybcio@linaro.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        "Lorenzo
 Pieralisi" <lpieralisi@kernel.org>,
        =?UTF-8?Q?Krzysztof_Wilczy=c5=84ski?=
	<kw@linux.com>,
        Rob Herring <robh@kernel.org>,
        Krzysztof Kozlowski
	<krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Manivannan Sadhasivam <mani@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Johan Hovold <johan+linaro@kernel.org>,
        Brian Masney <bmasney@redhat.com>, Georgi Djakov <djakov@kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <vireshk@kernel.org>,
        <quic_vbadigan@quicinc.com>, <quic_skananth@quicinc.com>,
        <quic_nitegupt@quicinc.com>, <linux-pci@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20240112165010.GA2271863@bhelgaas>
From: Krishna Chaitanya Chundru <quic_krichai@quicinc.com>
In-Reply-To: <20240112165010.GA2271863@bhelgaas>
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On 1/12/2024 10:20 PM, Bjorn Helgaas wrote:
> On Fri, Jan 12, 2024 at 07:52:05PM +0530, Krishna chaitanya chundru wrote:
>> QCOM Resource Power Manager-hardened (RPMh) is a hardware block which
>> maintains hardware state of a regulator by performing max aggregation of
>> the requests made by all of the processors.
>>
>> PCIe controller can operate on different RPMh performance state of power
>> domain based up on the speed of the link. And this performance state varies
>> from target to target.
>>
>> It is manadate to scale the performance state based up on the PCIe speed
>> link operates so that SoC can run under optimum power conditions.
>>
>> Add Operating Performance Points(OPP) support to vote for RPMh state based
>> upon GEN speed link is operating.
> 
> Thanks for this "OPP" expansion!  Maybe "GEN" is unnecessary in this
> sentence?  And below, could be replaced with actual speeds?
> 
ACK
>> OPP can handle ICC bw voting also, so move icc bw voting through opp
>> framework if opp entries are present.
> 
> s/opp/OPP/ to match
> s/icc/ICC/ similarly (and perhaps expand once)
> Also below in comments, etc.
> 
ACK.

-Krishna Chaitanya.
>> In PCIe certain gen speeds like GEN1x2 & GEN2X1 or GEN3x2 & GEN4x1 use
>> same icc bw and has frequency, so use frequency based search to reduce
>> number of entries in the opp table.
>>
>> Don't initialize icc if opp is supported.
> 
> Bjorn