linux-kernel - Re: [PATCH 0/3] opp: Add bw_factor support to adjust bandwidth dynamically

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Message-ID: <20250801085628.7gdqycsggnqxdr67@vireshk-i7>
Date: Fri, 1 Aug 2025 14:26:28 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
Cc: Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
	Stephen Boyd <sboyd@...nel.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	Manivannan Sadhasivam <mani@...nel.org>,
	Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Krzysztof Wilczyński <kwilczynski@...nel.org>,
	Rob Herring <robh@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
	Bjorn Andersson <andersson@...nel.org>,
	Konrad Dybcio <konradybcio@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH 0/3] opp: Add bw_factor support to adjust bandwidth
 dynamically

On 01-08-25, 13:58, Krishna Chaitanya Chundru wrote:
> When ever PCIe link speed/width changes we need to update the OPP votes,
> If we use named properties approach we might not be able to change it
> dynamically without removing the OPP table first. For that reason only
> we haven't used that approach.

I am not sure I understand it fully. I thought this was a one time configuration
you were required to do at boot time based on platform's configuration.

If you need to change the performance at runtime, won't you switch to a
different OPP ?

I don't have much knowledge of how PCIe works, maybe that's why the confusion.

-- 
viresh