PCI: imx6: Fix resource leaks in probe error paths

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_action() 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.

Fixes: 2c5768344f88 ("PCI: imx6: Move pci_pwrctrl_create_devices() to imx_pcie_probe()")
Reported-by: sashiko-bot@kernel.org
Link: https://lore.kernel.org/all/20260822013640.182C01F000E9@smtp.kernel.org/
Signed-off-by: Zhijian Han <hanzhijian1991@gmail.com>
[mani: removed the imx_pcie_detach_pd() helper]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
[bhelgaas: update commit log to match inlining of imx_pcie_detach_pd() into
imx_pcie_detach_pd_action()]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260904012307.3434449-1-hanzhijian1991@gmail.com

1 files changed, 43 insertions, 11 deletions

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 616c42932faa..6cf9106cce69 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_action(void *data)
+{
+	struct imx_pcie *imx_pcie = data;
+
+	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 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)
@@ -654,11 +682,11 @@ 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 |
-			DL_FLAG_PM_RUNTIME |
-			DL_FLAG_RPM_ACTIVE);
-	if (!link) {
+	imx_pcie->pd_link = device_link_add(dev, imx_pcie->pd_pcie,
+					    DL_FLAG_STATELESS |
+					    DL_FLAG_PM_RUNTIME |
+					    DL_FLAG_RPM_ACTIVE);
+	if (!imx_pcie->pd_link) {
 		dev_err(dev, "Failed to add device_link to pcie pd\n");
 		return -EINVAL;
 	}
@@ -667,11 +695,11 @@ static int imx_pcie_attach_pd(struct device *dev)
 	if (IS_ERR(imx_pcie->pd_pcie_phy))
 		return PTR_ERR(imx_pcie->pd_pcie_phy);
 
-	link = device_link_add(dev, imx_pcie->pd_pcie_phy,
-			DL_FLAG_STATELESS |
-			DL_FLAG_PM_RUNTIME |
-			DL_FLAG_RPM_ACTIVE);
-	if (!link) {
+	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 (!imx_pcie->pd_phy_link) {
 		dev_err(dev, "Failed to add device_link to pcie_phy pd\n");
 		return -EINVAL;
 	}
@@ -1951,6 +1979,10 @@ static int imx_pcie_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, imx_pcie);
 
+	ret = devm_add_action_or_reset(dev, imx_pcie_detach_pd_action, imx_pcie);
+	if (ret)
+		return ret;
+
 	ret = imx_pcie_attach_pd(dev);
 	if (ret)
 		return ret;