Re: [PATCH v2] schemas: pci: Document PCIe T_POWER_ON

[Lukas Wunner]

On Mon, Nov 10, 2025 at 04:59:47PM +0530, Krishna Chaitanya Chundru wrote:
> From PCIe r6, sec 5.5.4 & Table 5-11 in sec 5.5.5 T_POWER_ON is the

Please use the latest spec version as reference, i.e. PCIe r7.0.

> minimum amount of time(in us) that each component must wait in L1.2.Exit
> after sampling CLKREQ# asserted before actively driving the interface to
> ensure no device is ever actively driving into an unpowered component and
> these values are based on the components and AC coupling capacitors used
> in the connection linking the two components.
> 
> This property should be used to indicate the T_POWER_ON for each Root Port.

What's the difference between this property and the Port T_POWER_ON_Scale
and T_POWER_ON_Value in the L1 PM Substates Capabilities Register?

Why do you need this in the device tree even though it's available
in the register?

Thanks,

Lukas