Re: [PATCH v6 6/6] PCI: qcom: Add OPP support to scale performance state of power domain

From: Bjorn Helgaas
Date: Fri Jan 12 2024 - 11:50:27 EST


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?

> 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.

> 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