From 66caec3f005f3ae2a9cd3d131af710e60d246182 Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@ipxe.org>
Date: Tue, 25 Jan 2011 14:16:11 +0000
Subject: [PATCH] [netdevice] Allow devices to indicate that interrupts are not
 supported

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/include/ipxe/netdevice.h | 14 ++++++++++++++
 src/net/netdevice.c          |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/src/include/ipxe/netdevice.h b/src/include/ipxe/netdevice.h
index a7852a81..ac7cec52 100644
--- a/src/include/ipxe/netdevice.h
+++ b/src/include/ipxe/netdevice.h
@@ -236,6 +236,9 @@ struct net_device_operations {
 	 *
 	 * @v netdev	Network device
 	 * @v enable	Interrupts should be enabled
+	 *
+	 * This method may be NULL to indicate that interrupts are not
+	 * supported.
 	 */
 	void ( * irq ) ( struct net_device *netdev, int enable );
 };
@@ -515,6 +518,17 @@ netdev_is_open ( struct net_device *netdev ) {
 	return ( netdev->state & NETDEV_OPEN );
 }
 
+/**
+ * Check whether or not network device supports interrupts
+ *
+ * @v netdev		Network device
+ * @ret irq_supported	Network device supports interrupts
+ */
+static inline __attribute__ (( always_inline )) int
+netdev_irq_supported ( struct net_device *netdev ) {
+	return ( netdev->op->irq != NULL );
+}
+
 /**
  * Check whether or not network device interrupts are currently enabled
  *
diff --git a/src/net/netdevice.c b/src/net/netdevice.c
index c7e907ad..81382376 100644
--- a/src/net/netdevice.c
+++ b/src/net/netdevice.c
@@ -542,6 +542,10 @@ void unregister_netdev ( struct net_device *netdev ) {
  */
 void netdev_irq ( struct net_device *netdev, int enable ) {
 
+	/* Do nothing if device does not support interrupts */
+	if ( ! netdev_irq_supported ( netdev ) )
+		return;
+
 	/* Enable or disable device interrupts */
 	netdev->op->irq ( netdev, enable );