net: ethernet: cpsw: improve interrupt lookup logic in cpsw_probe()

Simplify the interrupt resource lookup code in cpsw_probe() by the
following:

 * Only look at the first member of the resource. As the driver only
   works for DT-enabled platforms anyway, a resource of type
   IORESOURCE_IRQ will only contain one single entry
   (res->start == res->end), so there is no need for the iteration.

 * Add a bounds check to avoid overflows if we are passed more than
   ARRAY_SIZE(priv->irqs_table) resources.

 * Assign 'ret' with the return value of devm_request_irq() so that
   cpsw_probe() returns the appropriate error code.

 * If devm_request_irq() fails, report the error code in the log
   message.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Mugunthan V N <mugunthanvnm@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 999fb72688d226317d0565c936a286386ae6dd98..03b409988566d33e04c2cf8d5566be1b4ac297d5 100644 (file)
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -2232,18 +2232,24 @@ static int cpsw_probe(struct platform_device *pdev)
        }
 
        while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k))) {
-               for (i = res->start; i <= res->end; i++) {
-                       if (devm_request_irq(&pdev->dev, i, cpsw_interrupt, 0,
-                                            dev_name(&pdev->dev), priv)) {
-                               dev_err(priv->dev, "error attaching irq\n");
-                               goto clean_ale_ret;
-                       }
-                       priv->irqs_table[k] = i;
-                       priv->num_irqs = k + 1;
+               if (k >= ARRAY_SIZE(priv->irqs_table)) {
+                       ret = -EINVAL;
+                       goto clean_ale_ret;
                }
+
+               ret = devm_request_irq(&pdev->dev, res->start, cpsw_interrupt,
+                                      0, dev_name(&pdev->dev), priv);
+               if (ret < 0) {
+                       dev_err(priv->dev, "error attaching irq (%d)\n", ret);
+                       goto clean_ale_ret;
+               }
+
+               priv->irqs_table[k] = res->start;
                k++;
        }
 
+       priv->num_irqs = k;
+
        ndev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
 
        ndev->netdev_ops = &cpsw_netdev_ops;