PCI: qcom: Fix error handling in runtime PM support

The driver does not cope with the fact that probe can fail in a number
of cases after enabling runtime PM on the device; this results in
warnings about "Unbalanced pm_runtime_enable". Furthermore if probe
fails after invoking qcom_pcie_host_init() the power-domain will be left
referenced.

As it is not possible for the error handling in qcom_pcie_host_init() to
handle errors happening after returning from that function the
pm_runtime_get_sync() is moved to qcom_pcie_probe() as well.

Fixes: 854b69ef ("PCI: qcom: add runtime pm support to pcie_port")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>

drivers/pci/controller/dwc/pcie-qcom.c

@@ -1089,7 +1089,6 @@ static int qcom_pcie_host_init(struct pcie_port *pp)
 	struct qcom_pcie *pcie = to_qcom_pcie(pci);
 	int ret;
 
-	pm_runtime_get_sync(pci->dev);
 	qcom_ep_reset_assert(pcie);
 
 	ret = pcie->ops->init(pcie);
@@ -1126,7 +1125,6 @@ static int qcom_pcie_host_init(struct pcie_port *pp)
 	phy_power_off(pcie->phy);
 err_deinit:
 	pcie->ops->deinit(pcie);
-	pm_runtime_put(pci->dev);
 
 	return ret;
 }
@@ -1216,6 +1214,12 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_disable(dev);
+		return ret;
+	}
+
 	pci->dev = dev;
 	pci->ops = &dw_pcie_ops;
 	pp = &pci->pp;
@@ -1225,44 +1229,56 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	pcie->ops = of_device_get_match_data(dev);
 
 	pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_LOW);
-	if (IS_ERR(pcie->reset))
-		return PTR_ERR(pcie->reset);
+	if (IS_ERR(pcie->reset)) {
+		ret = PTR_ERR(pcie->reset);
+		goto err_pm_runtime_put;
+	}
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "parf");
 	pcie->parf = devm_ioremap_resource(dev, res);
-	if (IS_ERR(pcie->parf))
-		return PTR_ERR(pcie->parf);
+	if (IS_ERR(pcie->parf)) {
+		ret = PTR_ERR(pcie->parf);
+		goto err_pm_runtime_put;
+	}
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
 	pci->dbi_base = devm_pci_remap_cfg_resource(dev, res);
-	if (IS_ERR(pci->dbi_base))
-		return PTR_ERR(pci->dbi_base);
+	if (IS_ERR(pci->dbi_base)) {
+		ret = PTR_ERR(pci->dbi_base);
+		goto err_pm_runtime_put;
+	}
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
 	pcie->elbi = devm_ioremap_resource(dev, res);
-	if (IS_ERR(pcie->elbi))
-		return PTR_ERR(pcie->elbi);
+	if (IS_ERR(pcie->elbi)) {
+		ret = PTR_ERR(pcie->elbi);
+		goto err_pm_runtime_put;
+	}
 
 	pcie->phy = devm_phy_optional_get(dev, "pciephy");
-	if (IS_ERR(pcie->phy))
-		return PTR_ERR(pcie->phy);
+	if (IS_ERR(pcie->phy)) {
+		ret = PTR_ERR(pcie->phy);
+		goto err_pm_runtime_put;
+	}
 
 	ret = pcie->ops->get_resources(pcie);
 	if (ret)
-		return ret;
+		goto err_pm_runtime_put;
 
 	pp->ops = &qcom_pcie_dw_ops;
 
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
-		if (pp->msi_irq < 0)
-			return pp->msi_irq;
+		if (pp->msi_irq < 0) {
+			ret = pp->msi_irq;
+			goto err_pm_runtime_put;
+		}
 	}
 
 	ret = phy_init(pcie->phy);
 	if (ret) {
 		pm_runtime_disable(&pdev->dev);
-		return ret;
+		goto err_pm_runtime_put;
 	}
 
 	platform_set_drvdata(pdev, pcie);
@@ -1271,10 +1287,16 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	if (ret) {
 		dev_err(dev, "cannot initialize host\n");
 		pm_runtime_disable(&pdev->dev);
-		return ret;
+		goto err_pm_runtime_put;
 	}
 
 	return 0;
+
+err_pm_runtime_put:
+	pm_runtime_put(dev);
+	pm_runtime_disable(dev);
+
+	return ret;
 }
 
 static const struct of_device_id qcom_pcie_match[] = {