From 910f793b0e368a93f7db6ed8eda920ecf147471e Mon Sep 17 00:00:00 2001
From: John Klug <john.klug@multitech.com>
Date: Fri, 4 Nov 2016 16:33:30 -0500
Subject: add Cadence ethernet patch.

---
 .../linux-3.12.27/linux-3.12-cadence-macb.patch    | 106 +++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 recipes-kernel/linux/linux-3.12.27/linux-3.12-cadence-macb.patch

diff --git a/recipes-kernel/linux/linux-3.12.27/linux-3.12-cadence-macb.patch b/recipes-kernel/linux/linux-3.12.27/linux-3.12-cadence-macb.patch
new file mode 100644
index 0000000..c814ed1
--- /dev/null
+++ b/recipes-kernel/linux/linux-3.12.27/linux-3.12-cadence-macb.patch
@@ -0,0 +1,106 @@
+--- linux-3.12.27/drivers/net/ethernet/cadence/macb.c	2014-08-26 07:12:26.000000000 -0500
++++ linux-3.12.27/drivers/net/ethernet/cadence/macb.c	2016-09-26 13:36:54.760657601 -0500
+@@ -755,7 +755,10 @@
+ 		unsigned int frag_len = bp->rx_buffer_size;
+ 
+ 		if (offset + frag_len > len) {
+-			BUG_ON(frag != last_frag);
++			if (unlikely(frag != last_frag)) {
++				dev_kfree_skb_any(skb);
++				return -1;
++			}
+ 			frag_len = len - offset;
+ 		}
+ 		skb_copy_to_linear_data_offset(skb, offset,
+@@ -783,11 +786,27 @@
+ 	return 0;
+ }
+ 
++static inline void macb_init_rx_ring(struct macb *bp)
++{
++	int i;
++	dma_addr_t addr;
++
++	addr = bp->rx_buffers_dma;
++	for (i = 0; i < RX_RING_SIZE; i++) {
++		bp->rx_ring[i].addr = addr;
++		bp->rx_ring[i].ctrl = 0;
++		addr += bp->rx_buffer_size;
++	}
++	bp->rx_ring[RX_RING_SIZE - 1].addr |= MACB_BIT(RX_WRAP);
++	bp->rx_tail = 0;
++}
++
+ static int macb_rx(struct macb *bp, int budget)
+ {
+ 	int received = 0;
+ 	unsigned int tail;
+ 	int first_frag = -1;
++	int reset_rx_queue = 0;
+ 
+ 	for (tail = bp->rx_tail; budget > 0; tail++) {
+ 		struct macb_dma_desc *desc = macb_rx_desc(bp, tail);
+@@ -810,10 +829,18 @@
+ 
+ 		if (ctrl & MACB_BIT(RX_EOF)) {
+ 			int dropped;
+-			BUG_ON(first_frag == -1);
++
++			if (unlikely(first_frag == -1)) {
++				reset_rx_queue = 1;
++				continue;
++			}
+ 
+ 			dropped = macb_rx_frame(bp, first_frag, tail);
+ 			first_frag = -1;
++			if (unlikely(dropped < 0)) {
++				reset_rx_queue = 1;
++				continue;
++			}
+ 			if (!dropped) {
+ 				received++;
+ 				budget--;
+@@ -821,6 +848,26 @@
+ 		}
+ 	}
+ 
++	if (unlikely(reset_rx_queue)) {
++		unsigned long flags;
++		u32 ctrl;
++
++		netdev_err(bp->dev, "RX queue corruption: reset it\n");
++
++		spin_lock_irqsave(&bp->lock, flags);
++
++		ctrl = macb_readl(bp, NCR);
++		macb_writel(bp, NCR, ctrl & ~MACB_BIT(RE));
++
++		macb_init_rx_ring(bp);
++		macb_writel(bp, RBQP, bp->rx_ring_dma);
++
++		macb_writel(bp, NCR, ctrl | MACB_BIT(RE));
++
++		spin_unlock_irqrestore(&bp->lock, flags);
++		return received;
++	}
++
+ 	if (first_frag != -1)
+ 		bp->rx_tail = first_frag;
+ 	else
+@@ -1189,15 +1236,8 @@
+ static void macb_init_rings(struct macb *bp)
+ {
+ 	int i;
+-	dma_addr_t addr;
+ 
+-	addr = bp->rx_buffers_dma;
+-	for (i = 0; i < RX_RING_SIZE; i++) {
+-		bp->rx_ring[i].addr = addr;
+-		bp->rx_ring[i].ctrl = 0;
+-		addr += bp->rx_buffer_size;
+-	}
+-	bp->rx_ring[RX_RING_SIZE - 1].addr |= MACB_BIT(RX_WRAP);
++	macb_init_rx_ring(bp);
+ 
+ 	for (i = 0; i < TX_RING_SIZE; i++) {
+ 		bp->tx_ring[i].addr = 0;
-- 
cgit v1.2.3