On Tue, Aug 31, 2010 at 03:41:22PM +0100, Ben Hutchings wrote:

On Mon, 2010-08-30 at 22:47 +0800, Liang Li wrote:

quoted

It's common sense that when we should do change to driver ring
desc/buffer etc only after 'stop/shutdown' the device. When we
do change while devices/driver is running, kernel oops occur:

[...]

quoted

diff --git a/drivers/net/ucc_geth_ethtool.c b/drivers/net/ucc_geth_ethtool.c
index 6f92e48..1b37aaa 100644
--- a/drivers/net/ucc_geth_ethtool.c
+++ b/drivers/net/ucc_geth_ethtool.c

@@ -255,13 +255,18 @@ uec_set_ringparam(struct net_device *netdev,
 		return -EINVAL;
 	}
 
-	ug_info->bdRingLenRx[queue] = ring->rx_pending;
-	ug_info->bdRingLenTx[queue] = ring->tx_pending;
-
 	if (netif_running(netdev)) {
-		/* FIXME: restart automatically */
-		printk(KERN_INFO
-			"Please re-open the interface.\n");
+		printk(KERN_INFO "Stopping interface %s.\n", netdev->name);
+		ucc_geth_close(netdev);
+
+		ug_info->bdRingLenRx[queue] = ring->rx_pending;
+		ug_info->bdRingLenTx[queue] = ring->tx_pending;
+
+		printk(KERN_INFO "Reactivating interface %s.\n", netdev->name);
+		ucc_geth_open(netdev);

What if ucc_geth_open() fails?

I did some runtime tests but did not witness the ucc_geth_open fail.
Assume it may fail for some reason, then I tend to think give out
warnings for request user to open/enable it mannually?  Or we may need
to keep the 'FIXME' line?

Thanks,
				-Liang Li

Ben.

quoted

+	} else {
+		ug_info->bdRingLenRx[queue] = ring->rx_pending;
+		ug_info->bdRingLenTx[queue] = ring->tx_pending;
 	}
 
 	return ret;

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.