Re: [PATCH V3 1/8] PCI: imx6: Add skip_pwrctrl_off flag support

[Frank Li]

On Fri, Jun 26, 2026 at 10:31:19AM +0800, Sherry Sun (OSS) wrote:
> From: Sherry Sun <sherry.sun@xxxxxxx>
>
> Use dw_pcie_rp::skip_pwrctrl_off to avoid powering off devices during
> suspend to preserve wakeup capability of the devices and also not to power
> on the devices in the init path.

Need empty line here.

> This allows controller power-off to be skipped when some devices(e.g. M.2
> cards key E without auxiliary power) required to support PCIe L2 link state
> and wake-up mechanisms.
>
> Move pci_pwrctrl_create_devices() to imx_pcie_probe() so that it is only
> called once during probe, similar to other regulator_get calls.
>
> Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 43 ++++++++++++++++-----------
>  1 file changed, 25 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 0fa716d1ed75..0685573fee71 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1382,16 +1382,12 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
>  		}
>  	}
>
> -	ret = pci_pwrctrl_create_devices(dev);
> -	if (ret) {
> -		dev_err(dev, "failed to create pwrctrl devices\n");
> -		goto err_reg_disable;
> -	}
> -

Please two patch do that. one patch move pci_pwrctrl_create_devices() to
probe

one patch check skip_power_off.

> -	ret = pci_pwrctrl_power_on_devices(dev);
> -	if (ret) {
> -		dev_err(dev, "failed to power on pwrctrl devices\n");
> -		goto err_pwrctrl_destroy;
> +	if (!pp->skip_pwrctrl_off) {
> +		ret = pci_pwrctrl_power_on_devices(dev);
> +		if (ret) {
> +			dev_err(dev, "failed to power on pwrctrl devices\n");
> +			goto err_reg_disable;
> +		}
>  	}
>
>  	ret = imx_pcie_clk_enable(imx_pcie);
> @@ -1460,10 +1456,8 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
>  err_clk_disable:
>  	imx_pcie_clk_disable(imx_pcie);
>  err_pwrctrl_power_off:
> -	pci_pwrctrl_power_off_devices(dev);
> -err_pwrctrl_destroy:
> -	if (ret != -EPROBE_DEFER)
> -		pci_pwrctrl_destroy_devices(dev);
> +	if (!pp->skip_pwrctrl_off)
> +		pci_pwrctrl_power_off_devices(dev);
>  err_reg_disable:
>  	if (imx_pcie->vpcie)
>  		regulator_disable(imx_pcie->vpcie);
> @@ -1482,7 +1476,8 @@ static void imx_pcie_host_exit(struct dw_pcie_rp *pp)
>  	}
>  	imx_pcie_clk_disable(imx_pcie);
>
> -	pci_pwrctrl_power_off_devices(pci->dev);
> +	if (!pci->pp.skip_pwrctrl_off)
> +		pci_pwrctrl_power_off_devices(pci->dev);
>  	if (imx_pcie->vpcie)
>  		regulator_disable(imx_pcie->vpcie);
>  }
> @@ -1954,11 +1949,15 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>
> +	ret = pci_pwrctrl_create_devices(dev);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to create pwrctrl devices\n");
> +
>  	pci->use_parent_dt_ranges = true;
>  	if (imx_pcie->drvdata->mode == DW_PCIE_EP_TYPE) {
>  		ret = imx_add_pcie_ep(imx_pcie, pdev);
>  		if (ret < 0)
> -			return ret;
> +			goto err_pwrctrl_destroy;
>
>  		/*
>  		 * FIXME: Only single Device (EPF) is supported due to the
> @@ -1973,7 +1972,7 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  		pci->pp.use_atu_msg = true;
>  		ret = dw_pcie_host_init(&pci->pp);
>  		if (ret < 0)
> -			return ret;
> +			goto err_pwrctrl_destroy;
>
>  		if (pci_msi_enabled()) {
>  			u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
> @@ -1985,16 +1984,24 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  	}
>
>  	return 0;
> +
> +err_pwrctrl_destroy:
> +	if (ret != -EPROBE_DEFER)
> +		pci_pwrctrl_destroy_devices(dev);
> +	return ret;

Mani said he will fix DEFER problem soon.

Frank

>  }
>
>  static void imx_pcie_shutdown(struct platform_device *pdev)
>  {
>  	struct imx_pcie *imx_pcie = platform_get_drvdata(pdev);
> +	struct dw_pcie *pci = imx_pcie->pci;
> +	struct dw_pcie_rp *pp = &pci->pp;
>
>  	/* bring down link, so bootloader gets clean state in case of reboot */
>  	imx_pcie_assert_core_reset(imx_pcie);
>  	imx_pcie_assert_perst(imx_pcie, true);
> -	pci_pwrctrl_power_off_devices(&pdev->dev);
> +	if (!pp->skip_pwrctrl_off)
> +		pci_pwrctrl_power_off_devices(&pdev->dev);
>  	pci_pwrctrl_destroy_devices(&pdev->dev);
>  }
>
> --
> 2.50.1
>
>