Re: [PATCH v3 5/5] PCI: qcom: Add D3cold support

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 3/11/26 11:26 AM, Krishna Chaitanya Chundru wrote:
> Add support for transitioning PCIe endpoints & bridges into D3cold by
> integrating with the DWC core suspend/resume helpers.
> 
> Implement PME_TurnOff message generation via ELBI_SYS_CTRL and hook it
> into the DWC host operations so the controller follows the standard
> PME_TurnOff-based power-down sequence before entering D3cold.
> 
> When the device is suspended into D3cold, fully tear down interconnect
> bandwidth, OPP votes. If D3cold is not entered, retain existing behavior
> by keeping the required interconnect and OPP votes.
> 
> Drop the qcom_pcie::suspended flag and rely on the existing
> dw_pcie::suspended state, which now drives both the power-management
> flow and the interconnect/OPP handling.
> 
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> ---

[...]

>  		ret = icc_disable(pcie->icc_cpu);
>  		if (ret)
>  			dev_err(dev, "Failed to disable CPU-PCIe interconnect path: %d\n", ret);
>  
>  		if (pcie->use_pm_opp)
>  			dev_pm_opp_set_opp(pcie->pci->dev, NULL);

Does calling .suspend not drop the vote by itself?

[...]

> @@ -2132,25 +2138,46 @@ static int qcom_pcie_resume_noirq(struct device *dev)

Similarly, I'd expect that .resume restores it (and you didn't do it manually)

Konrad