Re: [PATCH v6] PCI: imx6: fix resource leaks in probe error paths

[Frank Li <Frank.li@oss.nxp.com>]

On Fri, Sep 04, 2026 at 12:03:42AM +0800, Zhijian Han wrote:
> imx_pcie_probe() leaks both pwrctrl devices and power domains on failure:
>
> - imx_pcie_attach_pd() attaches the "pcie" and "pcie_phy" power domains
>   and adds device links to them, but nothing detaches the domains or
>   removes the links on probe failure or deferral, so they leak.
>
> - A failure of devm_pm_runtime_set_active_enabled() returns directly
>   without destroying the pwrctrl devices.
>
> - A partial failure inside imx_pcie_attach_pd() leaks the power domains
>   that were already attached.
>
> Add imx_pcie_detach_pd() to remove the device links and detach the power
> domains in reverse order of acquisition and register it with
> devm_add_action_or_reset() so they are released automatically on probe
> failure.
>
> Reported-by: sashiko-bot@kernel.org
> Link: https://lore.kernel.org/all/20260822013640.182C01F000E9@smtp.kernel.org/
> Fixes: 2c5768344f88 ("PCI: imx6: Move pci_pwrctrl_create_devices() to imx_pcie_probe()")
> Signed-off-by: Zhijian Han <hanzhijian1991@gmail.com>
> ---
> Changes in v6:
> - Keep the device links stateless and remove them with device_link_del()
>   in imx_pcie_detach_pd() instead of using DL_FLAG_AUTOREMOVE_CONSUMER,
>   which creates managed links to power-domain devices that never bind a
>   driver and would trigger a WARN_ON in device_links_driver_bound()
>
> Changes in v5:
> - Register imx_pcie_detach_pd() with devm_add_action_or_reset() instead
>   of calling it manually on the error paths
>
>  drivers/pci/controller/dwc/pci-imx6.c | 58 ++++++++++++++++++++++-----
>  1 file changed, 48 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 39790e66b98d..7dd22b4f826a 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -180,8 +180,12 @@ struct imx_pcie {
>  	struct imx_lut_data	luts[IMX95_MAX_LUT];
>  	/* power domain for pcie */
>  	struct device		*pd_pcie;
> +	/* device link for pcie power domain */
> +	struct device_link	*pd_link;
>  	/* power domain for pcie phy */
>  	struct device		*pd_pcie_phy;
> +	/* device link for pcie phy power domain */
> +	struct device_link	*pd_phy_link;
>  	struct phy		*phy;
>  	const struct imx_pcie_drvdata *drvdata;
>
> @@ -639,10 +643,34 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
>  }
>  #endif
>
> +static void imx_pcie_detach_pd(struct imx_pcie *imx_pcie)
> +{
> +	if (!IS_ERR_OR_NULL(imx_pcie->pd_phy_link)) {
> +		device_link_del(imx_pcie->pd_phy_link);
> +		imx_pcie->pd_phy_link = NULL;
> +	}
> +	if (!IS_ERR_OR_NULL(imx_pcie->pd_link)) {
> +		device_link_del(imx_pcie->pd_link);
> +		imx_pcie->pd_link = NULL;
> +	}
> +	if (!IS_ERR_OR_NULL(imx_pcie->pd_pcie_phy)) {
> +		dev_pm_domain_detach(imx_pcie->pd_pcie_phy, true);
> +		imx_pcie->pd_pcie_phy = NULL;
> +	}
> +	if (!IS_ERR_OR_NULL(imx_pcie->pd_pcie)) {
> +		dev_pm_domain_detach(imx_pcie->pd_pcie, true);
> +		imx_pcie->pd_pcie = NULL;
> +	}
> +}
> +
> +static void imx_pcie_detach_pd_action(void *data)
> +{
> +	imx_pcie_detach_pd(data);
> +}
> +
>  static int imx_pcie_attach_pd(struct device *dev)
>  {
>  	struct imx_pcie *imx_pcie = dev_get_drvdata(dev);
> -	struct device_link *link;
>
>  	/* Do nothing when in a single power domain */
>  	if (dev->pm_domain)
> @@ -654,25 +682,31 @@ static int imx_pcie_attach_pd(struct device *dev)
>  	/* Do nothing when power domain missing */
>  	if (!imx_pcie->pd_pcie)
>  		return 0;
> -	link = device_link_add(dev, imx_pcie->pd_pcie,
> -			DL_FLAG_STATELESS |
> +	imx_pcie->pd_link = device_link_add(dev, imx_pcie->pd_pcie,
> +					    DL_FLAG_STATELESS |
>  			DL_FLAG_PM_RUNTIME |
>  			DL_FLAG_RPM_ACTIVE);
> -	if (!link) {
> +	if (!imx_pcie->pd_link) {
>  		dev_err(dev, "Failed to add device_link to pcie pd\n");
> +		imx_pcie_detach_pd(imx_pcie);
>  		return -EINVAL;
>  	}
>
>  	imx_pcie->pd_pcie_phy = dev_pm_domain_attach_by_name(dev, "pcie_phy");
> -	if (IS_ERR(imx_pcie->pd_pcie_phy))
> -		return PTR_ERR(imx_pcie->pd_pcie_phy);
> +	if (IS_ERR(imx_pcie->pd_pcie_phy)) {
> +		int ret = PTR_ERR(imx_pcie->pd_pcie_phy);
> +
> +		imx_pcie_detach_pd(imx_pcie);
> +		return ret;
> +	}
>
> -	link = device_link_add(dev, imx_pcie->pd_pcie_phy,
> -			DL_FLAG_STATELESS |
> +	imx_pcie->pd_phy_link = device_link_add(dev, imx_pcie->pd_pcie_phy,
> +						DL_FLAG_STATELESS |
>  			DL_FLAG_PM_RUNTIME |
>  			DL_FLAG_RPM_ACTIVE);
> -	if (!link) {
> +	if (!imx_pcie->pd_phy_link) {
>  		dev_err(dev, "Failed to add device_link to pcie_phy pd\n");
> +		imx_pcie_detach_pd(imx_pcie);
>  		return -EINVAL;
>  	}
>
> @@ -1955,6 +1989,10 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>
> +	ret = devm_add_action_or_reset(dev, imx_pcie_detach_pd_action, imx_pcie);
> +	if (ret)
> +		return ret;
> +

because there is safe guide in imx_pcie_detac_pd_action(), if move it before
imx_pcie_attach_pd(),  Needn't call imx_pcie_detach_pd() in error path.

Or use goto in for error handle in imx_pcie_attach_pd() instead of duplicate
call each error branch.

Frank

>  	ret = pci_pwrctrl_create_devices(dev);
>  	if (ret)
>  		return dev_err_probe(dev, ret, "failed to create pwrctrl devices\n");
> @@ -1975,7 +2013,7 @@ static int imx_pcie_probe(struct platform_device *pdev)
>  			pm_runtime_no_callbacks(dev);
>  			ret = devm_pm_runtime_set_active_enabled(dev);
>  			if (ret < 0)
> -				return ret;
> +				goto err_pwrctrl_destroy;
>  		}
>
>  		if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_SKIP_L23_READY))
>