[dpdk-dev] [PATCH 05/10] igb_uio: propogate error numbers in probe code

[Stephen Hemminger <stephen@networkplumber.org>]

[-- Attachment #1: igb_uio-error-handling.patch --]
[-- Type: text/plain, Size: 3145 bytes --]

It is good practice to propogate the return values of failing
functions so that more information can be reported. The failed result
of probe will make it out to errno and get printed by modprobe
and will aid in diagnosis of failures.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>


--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c	2014-07-18 08:42:22.856545033 -0700
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c	2014-07-18 08:42:47.500631562 -0700
@@ -518,7 +518,7 @@ igbuio_setup_bars(struct pci_dev *dev, s
 		}
 	}
 
-	return ((iom != 0) ? ret : ENOENT);
+	return (iom != 0) ? ret : -ENOENT;
 }
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,8,0)
@@ -530,6 +530,7 @@ igbuio_pci_probe(struct pci_dev *dev, co
 {
 	struct rte_uio_pci_dev *udev;
 	struct msix_entry msix_entry;
+	int err;
 
 	udev = kzalloc(sizeof(struct rte_uio_pci_dev), GFP_KERNEL);
 	if (!udev)
@@ -539,7 +540,8 @@ igbuio_pci_probe(struct pci_dev *dev, co
 	 * enable device: ask low-level code to enable I/O and
 	 * memory
 	 */
-	if (pci_enable_device(dev)) {
+	err = pci_enable_device(dev);
+	if (err != 0) {
 		dev_err(&dev->dev, "Cannot enable PCI device\n");
 		goto fail_free;
 	}
@@ -548,7 +550,8 @@ igbuio_pci_probe(struct pci_dev *dev, co
 	 * reserve device's PCI memory regions for use by this
 	 * module
 	 */
-	if (pci_request_regions(dev, "igb_uio")) {
+	err = pci_request_regions(dev, "igb_uio");
+	if (err != 0) {
 		dev_err(&dev->dev, "Cannot request regions\n");
 		goto fail_disable;
 	}
@@ -557,14 +560,19 @@ igbuio_pci_probe(struct pci_dev *dev, co
 	pci_set_master(dev);
 
 	/* remap IO memory */
-	if (igbuio_setup_bars(dev, &udev->info))
+	err = igbuio_setup_bars(dev, &udev->info);
+	if (err != 0)
 		goto fail_release_iomem;
 
 	/* set 64-bit DMA mask */
-	if (pci_set_dma_mask(dev,  DMA_BIT_MASK(64))) {
+	err = pci_set_dma_mask(dev,  DMA_BIT_MASK(64));
+	if (err != 0) {
 		dev_err(&dev->dev, "Cannot set DMA mask\n");
 		goto fail_release_iomem;
-	} else if (pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(64))) {
+	}
+
+	err = pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(64));
+	if (err != 0) {
 		dev_err(&dev->dev, "Cannot set consistent DMA mask\n");
 		goto fail_release_iomem;
 	}
@@ -613,19 +621,22 @@ igbuio_pci_probe(struct pci_dev *dev, co
 	pci_set_drvdata(dev, udev);
 	igbuio_pci_irqcontrol(&udev->info, 0);
 
-	if (sysfs_create_group(&dev->dev.kobj, &dev_attr_grp))
+	err = sysfs_create_group(&dev->dev.kobj, &dev_attr_grp);
+	if (err != 0)
 		goto fail_release_iomem;
 
 	/* register uio driver */
-	if (uio_register_device(&dev->dev, &udev->info))
-		goto fail_release_iomem;
+	err = uio_register_device(&dev->dev, &udev->info);
+	if (err != 0)
+		goto fail_remove_group;
 
 	printk(KERN_INFO "uio device registered with irq %lx\n", udev->info.irq);
 
 	return 0;
 
-fail_release_iomem:
+fail_remove_group:
 	sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp);
+fail_release_iomem:
 	igbuio_pci_release_iomem(&udev->info);
 	if (udev->mode == RTE_INTR_MODE_MSIX)
 		pci_disable_msix(udev->pdev);
@@ -635,7 +646,7 @@ fail_disable:
 fail_free:
 	kfree(udev);
 
-	return -ENODEV;
+	return err;
 }
 
 static void