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/[e-mail]
[bhelgaas: commit log, squash into one patch]
Signed-off-by: Aman Sharma <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Cc: Richard Zhu <[e-mail]>
Cc: Lucas Stach <[e-mail]>
Cc: Thierry Reding <[e-mail]>
Cc: Karthikeyan Mitran <[e-mail]>
Cc: Hou Zhiqiang <[e-mail]>
Cc: Thomas Petazzoni <[e-mail]>
Cc: Ryder Lee <[e-mail]>
Cc: Marc Gonzalez <[e-mail]>

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

···
 
 	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

···
 	}
 
 	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

···
 	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

···
 		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

···
 
 	/* 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

···
 	}
 
 	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

···
 		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);