net/sonic: Fix receive buffer handling
The SONIC can sometimes advance its rx buffer pointer (RRP register)
without advancing its rx descriptor pointer (CRDA register). As a result
the index of the current rx descriptor may not equal that of the current
rx buffer. The driver mistakenly assumes that they are always equal.
This assumption leads to incorrect packet lengths and possible packet
duplication. Avoid this by calling a new function to locate the buffer
corresponding to a given descriptor.
Fixes: efcce839360f ("[PATCH] macsonic/jazzsonic network drivers update")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/natsemi/sonic.c b/drivers/net/ethernet/natsemi/sonic.c
index b31c7af..c666bbf1 100644
--- a/drivers/net/ethernet/natsemi/sonic.c
+++ b/drivers/net/ethernet/natsemi/sonic.c
@@ -413,6 +413,21 @@
return IRQ_HANDLED;
}
+/* Return the array index corresponding to a given Receive Buffer pointer. */
+static int index_from_addr(struct sonic_local *lp, dma_addr_t addr,
+ unsigned int last)
+{
+ unsigned int i = last;
+
+ do {
+ i = (i + 1) & SONIC_RRS_MASK;
+ if (addr == lp->rx_laddr[i])
+ return i;
+ } while (i != last);
+
+ return -ENOENT;
+}
+
/*
* We have a good packet(s), pass it/them up the network stack.
*/
@@ -432,6 +447,16 @@
status = sonic_rda_get(dev, entry, SONIC_RD_STATUS);
if (status & SONIC_RCR_PRX) {
+ u32 addr = (sonic_rda_get(dev, entry,
+ SONIC_RD_PKTPTR_H) << 16) |
+ sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_L);
+ int i = index_from_addr(lp, addr, entry);
+
+ if (i < 0) {
+ WARN_ONCE(1, "failed to find buffer!\n");
+ break;
+ }
+
/* Malloc up new buffer. */
new_skb = netdev_alloc_skb(dev, SONIC_RBSIZE + 2);
if (new_skb == NULL) {
@@ -453,7 +478,7 @@
/* now we have a new skb to replace it, pass the used one up the stack */
dma_unmap_single(lp->device, lp->rx_laddr[entry], SONIC_RBSIZE, DMA_FROM_DEVICE);
- used_skb = lp->rx_skb[entry];
+ used_skb = lp->rx_skb[i];
pkt_len = sonic_rda_get(dev, entry, SONIC_RD_PKTLEN);
skb_trim(used_skb, pkt_len);
used_skb->protocol = eth_type_trans(used_skb, dev);
@@ -462,13 +487,13 @@
lp->stats.rx_bytes += pkt_len;
/* and insert the new skb */
- lp->rx_laddr[entry] = new_laddr;
- lp->rx_skb[entry] = new_skb;
+ lp->rx_laddr[i] = new_laddr;
+ lp->rx_skb[i] = new_skb;
bufadr_l = (unsigned long)new_laddr & 0xffff;
bufadr_h = (unsigned long)new_laddr >> 16;
- sonic_rra_put(dev, entry, SONIC_RR_BUFADR_L, bufadr_l);
- sonic_rra_put(dev, entry, SONIC_RR_BUFADR_H, bufadr_h);
+ sonic_rra_put(dev, i, SONIC_RR_BUFADR_L, bufadr_l);
+ sonic_rra_put(dev, i, SONIC_RR_BUFADR_H, bufadr_h);
} else {
/* This should only happen, if we enable accepting broken packets. */
}
diff --git a/drivers/net/ethernet/natsemi/sonic.h b/drivers/net/ethernet/natsemi/sonic.h
index 9e4ff8d..e6d47e4 100644
--- a/drivers/net/ethernet/natsemi/sonic.h
+++ b/drivers/net/ethernet/natsemi/sonic.h
@@ -275,8 +275,9 @@
#define SONIC_NUM_RDS SONIC_NUM_RRS /* number of receive descriptors */
#define SONIC_NUM_TDS 16 /* number of transmit descriptors */
-#define SONIC_RDS_MASK (SONIC_NUM_RDS-1)
-#define SONIC_TDS_MASK (SONIC_NUM_TDS-1)
+#define SONIC_RRS_MASK (SONIC_NUM_RRS - 1)
+#define SONIC_RDS_MASK (SONIC_NUM_RDS - 1)
+#define SONIC_TDS_MASK (SONIC_NUM_TDS - 1)
#define SONIC_RBSIZE 1520 /* size of one resource buffer */
