Re: [PATCH v3 1/2] dt-bindings: PCI: mediatek-gen3: Add property to disable dvfsrc voltage request

From: Rob Herring
Date: Fri Jul 16 2021 - 13:33:45 EST


On Wed, Jun 30, 2021 at 10:49:33AM +0800, Jianjun Wang wrote:
> Add property to disable dvfsrc voltage request, if this property
> is presented, we assume that the requested voltage is always
> higher enough to keep the PCIe controller active.
>
> Signed-off-by: Jianjun Wang <jianjun.wang@xxxxxxxxxxxx>
> ---
> .../devicetree/bindings/pci/mediatek-pcie-gen3.yaml | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> index e7b1f9892da4..3e26c032cea9 100644
> --- a/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> +++ b/Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.yaml
> @@ -96,6 +96,12 @@ properties:
> phys:
> maxItems: 1
>
> + disable-dvfsrc-vlt-req:
> + description: Disable dvfsrc voltage request, if this property is presented,
> + we assume that the requested voltage is always higher enough to keep
> + the PCIe controller active.
> + type: boolean

What determines setting this property? Can it be implied by the
compatible (which should be SoC specific).

Is this property specific to PCIe controller?

Wouldn't the request be harmless to make the voltage request even if not
needed?

I think this probably should be addressed in a common way as part of
other QoS, devfreq, etc. requirements for devices.

Rob