mcb: mcb-pci: detect IO mapped devices before requesting resources

If the memory region is requested with devm_request_mem_region()
for an IO mapped device it will return an error and mcb-pci will
incorrectly report it with EBUSY code.

Make sure we identify if the reosure is IO mapped and fail early
with a correct ENOTSUPP code.
Reviewed-by: Jose Javier Rodriguez Barbarin <JoseJavier.Rodriguez@duagon.com>
Signed-off-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
Link: https://lore.kernel.org/r/20240523103430.423340-1-jorge.sanjuangarcia@duagon.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mcb/mcb-pci.c

@@ -45,6 +45,14 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	}
 	pci_set_master(pdev);
 
+	flags = pci_resource_flags(pdev, 0);
+	if (flags & IORESOURCE_IO) {
+		ret = -ENOTSUPP;
+		dev_err(&pdev->dev,
+			"IO mapped PCI devices are not supported\n");
+		goto out_disable;
+	}
+
 	priv->mapbase = pci_resource_start(pdev, 0);
 	if (!priv->mapbase) {
 		dev_err(&pdev->dev, "No PCI resource\n");
@@ -68,14 +76,6 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		goto out_disable;
 	}
 
-	flags = pci_resource_flags(pdev, 0);
-	if (flags & IORESOURCE_IO) {
-		ret = -ENOTSUPP;
-		dev_err(&pdev->dev,
-			"IO mapped PCI devices are not supported\n");
-		goto out_disable;
-	}
-
 	pci_set_drvdata(pdev, priv);
 
 	priv->bus = mcb_alloc_bus(&pdev->dev);