From ef59a8109ff2c382949baf9dc103f1440d9bfb6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>
Date: Mon, 28 Jan 2013 23:51:28 +0000
Subject: [PATCH] --- yaml --- r: 349633 b: refs/heads/master c:
 70c37bf97f2a91accba76080db69144f3b69f736 h: refs/heads/master i:   349631:
 1dc92fb4c189fb40e2196636be3d9b508dbd642e v: v3

---
 [refs]                           |  2 +-
 trunk/drivers/net/usb/usbnet.c   | 25 +++++++++++++++++++++++++
 trunk/include/linux/usb/usbnet.h |  2 ++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index e607ae16249b..ad470071e18b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6cdd20c380eb62eab757c5a6ccc90dac7ecd774b
+refs/heads/master: 70c37bf97f2a91accba76080db69144f3b69f736
diff --git a/trunk/drivers/net/usb/usbnet.c b/trunk/drivers/net/usb/usbnet.c
index f34b2ebee815..977837725726 100644
--- a/trunk/drivers/net/usb/usbnet.c
+++ b/trunk/drivers/net/usb/usbnet.c
@@ -380,6 +380,12 @@ static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 	unsigned long		lockflags;
 	size_t			size = dev->rx_urb_size;
 
+	/* prevent rx skb allocation when error ratio is high */
+	if (test_bit(EVENT_RX_KILL, &dev->flags)) {
+		usb_free_urb(urb);
+		return -ENOLINK;
+	}
+
 	skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 	if (!skb) {
 		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
@@ -539,6 +545,17 @@ static void rx_complete (struct urb *urb)
 		break;
 	}
 
+	/* stop rx if packet error rate is high */
+	if (++dev->pkt_cnt > 30) {
+		dev->pkt_cnt = 0;
+		dev->pkt_err = 0;
+	} else {
+		if (state == rx_cleanup)
+			dev->pkt_err++;
+		if (dev->pkt_err > 20)
+			set_bit(EVENT_RX_KILL, &dev->flags);
+	}
+
 	state = defer_bh(dev, skb, &dev->rxq, state);
 
 	if (urb) {
@@ -791,6 +808,11 @@ int usbnet_open (struct net_device *net)
 		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 		   "simple");
 
+	/* reset rx error state */
+	dev->pkt_cnt = 0;
+	dev->pkt_err = 0;
+	clear_bit(EVENT_RX_KILL, &dev->flags);
+
 	// delay posting reads until we're fully open
 	tasklet_schedule (&dev->bh);
 	if (info->manage_power) {
@@ -1254,6 +1276,9 @@ static void usbnet_bh (unsigned long param)
 		}
 	}
 
+	/* restart RX again after disabling due to high error rate */
+	clear_bit(EVENT_RX_KILL, &dev->flags);
+
 	// waiting for all pending urbs to complete?
 	if (dev->wait) {
 		if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
diff --git a/trunk/include/linux/usb/usbnet.h b/trunk/include/linux/usb/usbnet.h
index 5de7a220e986..0de078d4cdb9 100644
--- a/trunk/include/linux/usb/usbnet.h
+++ b/trunk/include/linux/usb/usbnet.h
@@ -33,6 +33,7 @@ struct usbnet {
 	wait_queue_head_t	*wait;
 	struct mutex		phy_mutex;
 	unsigned char		suspend_count;
+	unsigned char		pkt_cnt, pkt_err;
 
 	/* i/o info: pipes etc */
 	unsigned		in, out;
@@ -70,6 +71,7 @@ struct usbnet {
 #		define EVENT_DEV_OPEN	7
 #		define EVENT_DEVICE_REPORT_IDLE	8
 #		define EVENT_NO_RUNTIME_PM	9
+#		define EVENT_RX_KILL	10
 };
 
 static inline struct usb_driver *driver_of(struct usb_interface *intf)