PCI: Check for platform_get_irq() failure consistently

The platform_get_irq*() interfaces return either a negative error number or
a valid IRQ.  0 is not a valid return value, so check for "< 0" to detect
failure as recommended by the function documentation.

On failure, return the error number from platform_get_irq*() instead of
making up a new one.

Link: https://lore.kernel.org/r/cover.1583952275.git.amanharitsh123@gmail.com
[bhelgaas: commit log, squash into one patch]
Signed-off-by: Aman Sharma <amanharitsh123@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>
Cc: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Marc Gonzalez <marc.w.gonzalez@free.fr>

drivers/pci/controller/dwc/pci-imx6.c

@@ -868,9 +868,9 @@ static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
 
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
-		if (pp->msi_irq <= 0) {
+		if (pp->msi_irq < 0) {
 			dev_err(dev, "failed to get MSI irq\n");
-			return -ENODEV;
+			return pp->msi_irq;
 		}
 	}
 

drivers/pci/controller/dwc/pcie-tegra194.c

@@ -2190,9 +2190,9 @@ static int tegra_pcie_dw_probe(struct platform_device *pdev)
 	}
 
 	pp->irq = platform_get_irq_byname(pdev, "intr");
-	if (!pp->irq) {
+	if (pp->irq < 0) {
 		dev_err(dev, "Failed to get \"intr\" interrupt\n");
-		return -ENODEV;
+		return pp->irq;
 	}
 
 	pcie->bpmp = tegra_bpmp_get(dev);

drivers/pci/controller/mobiveil/pcie-mobiveil-host.c

@@ -522,9 +522,9 @@ static int mobiveil_pcie_integrated_interrupt_init(struct mobiveil_pcie *pcie)
 	mobiveil_pcie_enable_msi(pcie);
 
 	rp->irq = platform_get_irq(pdev, 0);
-	if (rp->irq <= 0) {
+	if (rp->irq < 0) {
 		dev_err(dev, "failed to map IRQ: %d\n", rp->irq);
-		return -ENODEV;
+		return rp->irq;
 	}
 
 	/* initialize the IRQ domains */

drivers/pci/controller/pci-aardvark.c

@@ -973,6 +973,9 @@ static int advk_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(pcie->base);
 
 	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
 	ret = devm_request_irq(dev, irq, advk_pcie_irq_handler,
 			       IRQF_SHARED | IRQF_NO_THREAD, "advk-pcie",
 			       pcie);

drivers/pci/controller/pci-v3-semi.c

@@ -777,9 +777,9 @@ static int v3_pci_probe(struct platform_device *pdev)
 
 	/* Get and request error IRQ resource */
 	irq = platform_get_irq(pdev, 0);
-	if (irq <= 0) {
+	if (irq < 0) {
 		dev_err(dev, "unable to obtain PCIv3 error IRQ\n");
-		return -ENODEV;
+		return irq;
 	}
 	ret = devm_request_irq(dev, irq, v3_irq, 0,
 			"PCIv3 error", v3);

drivers/pci/controller/pcie-mediatek.c

@@ -651,6 +651,9 @@ static int mtk_pcie_setup_irq(struct mtk_pcie_port *port,
 	}
 
 	port->irq = platform_get_irq(pdev, port->slot);
+	if (port->irq < 0)
+		return port->irq;
+
 	irq_set_chained_handler_and_data(port->irq,
 					 mtk_pcie_intr_handler, port);
 

drivers/pci/controller/pcie-tango.c

@@ -273,9 +273,9 @@ static int tango_pcie_probe(struct platform_device *pdev)
 		writel_relaxed(0, pcie->base + SMP8759_ENABLE + offset);
 
 	virq = platform_get_irq(pdev, 1);
-	if (virq <= 0) {
+	if (virq < 0) {
 		dev_err(dev, "Failed to map IRQ\n");
-		return -ENXIO;
+		return virq;
 	}
 
 	irq_dom = irq_domain_create_linear(fwnode, MSI_MAX, &dom_ops, pcie);