On Tue, Apr 03, 2012 at 04:58:45PM +0600, Mike Sinkovsky wrote:

+static irqreturn_t w5300_detect_link(int irq, void *ndev_instance)
+{
+	struct net_device *ndev = ndev_instance;
+	struct w5300_priv *priv = netdev_priv(ndev);
+
+	if (netif_running(ndev)) {
+		if (gpio_get_value(priv->link_gpio) != 0) {
+			netif_info(priv, link, ndev, "link is up\n");
+			netif_carrier_on(ndev);
+		} else {
+			netif_info(priv, link, ndev, "link is down\n");
+			netif_carrier_off(ndev);
+		}
+	}
+
+	return IRQ_HANDLED;
+}

This relies on ndev being valid and on the gpio being requested but...

+	priv->link_gpio = data->link_gpio;
+	if (gpio_is_valid(priv->link_gpio)) {
+		char *link_name = devm_kzalloc(&pdev->dev, 16, GFP_KERNEL);
+		if (!link_name)
+			return -ENOMEM;
+		snprintf(link_name, 16, "%s-link", name);
+		priv->link_irq = gpio_to_irq(priv->link_gpio);
+		if (devm_request_threaded_irq(&pdev->dev,
+				priv->link_irq, NULL, w5300_detect_link,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+				link_name, priv->ndev) < 0)
+			priv->link_gpio = -EINVAL;
+	}

...you use devm_request_threaded_irq() here and rely on it for cleanup.
Are you sure there's no possibility of the interrupt firing after you
start to tear down the device?

By using a specifically threaded IRQ you're also adding a performance
overhead for no good reason if you can call netdev_carrier_*() from IRQ
context and the GPIO is capable of generating a hard IRQ.  If you use
request_any_context_irq() instead then the driver will get a hard IRQ if
that's supported.