e1000e: fix dma error handling issues
There were a few issues I noticed in e1000e. These include a double free
of the skb if mapping fails, and the fact that context descriptors appear
to be left in the descriptor ring after the failure.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index 402d2dd..da876d5 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -574,6 +574,7 @@
dev_kfree_skb_any(buffer_info->skb);
buffer_info->skb = NULL;
}
+ buffer_info->time_stamp = 0;
}
static void e1000_print_tx_hang(struct e1000_adapter *adapter)
@@ -678,17 +679,10 @@
}
if (adapter->detect_tx_hung) {
- /*
- * Detect a transmit hang in hardware, this serializes the
- * check with the clearing of time_stamp and movement of i
- */
+ /* Detect a transmit hang in hardware, this serializes the
+ * check with the clearing of time_stamp and movement of i */
adapter->detect_tx_hung = 0;
- /*
- * read barrier to make sure that the ->dma member and time
- * stamp are updated fully
- */
- smp_rmb();
- if (tx_ring->buffer_info[eop].dma &&
+ if (tx_ring->buffer_info[eop].time_stamp &&
time_after(jiffies, tx_ring->buffer_info[eop].time_stamp
+ (adapter->tx_timeout_factor * HZ))
&& !(er32(STATUS) & E1000_STATUS_TXOFF)) {
@@ -3824,39 +3818,41 @@
unsigned int mss)
{
struct e1000_ring *tx_ring = adapter->tx_ring;
+ struct e1000_buffer *buffer_info;
unsigned int len = skb_headlen(skb);
unsigned int offset, size, count = 0, i;
unsigned int f;
- dma_addr_t map;
+ dma_addr_t *map;
i = tx_ring->next_to_use;
if (skb_dma_map(&adapter->pdev->dev, skb, DMA_TO_DEVICE)) {
dev_err(&adapter->pdev->dev, "TX DMA map failed\n");
adapter->tx_dma_failed++;
- dev_kfree_skb(skb);
- return -2;
+ return 0;
}
- map = skb_shinfo(skb)->dma_maps[0];
+ map = skb_shinfo(skb)->dma_maps;
offset = 0;
while (len) {
- struct e1000_buffer *buffer_info = &tx_ring->buffer_info[i];
+ buffer_info = &tx_ring->buffer_info[i];
size = min(len, max_per_txd);
buffer_info->length = size;
- /* set time_stamp *before* dma to help avoid a possible race */
buffer_info->time_stamp = jiffies;
- buffer_info->dma = map + offset;
buffer_info->next_to_watch = i;
+ buffer_info->dma = map[0] + offset;
+ count++;
len -= size;
offset += size;
- count++;
- i++;
- if (i == tx_ring->count)
- i = 0;
+
+ if (len) {
+ i++;
+ if (i == tx_ring->count)
+ i = 0;
+ }
}
for (f = 0; f < nr_frags; f++) {
@@ -3864,37 +3860,29 @@
frag = &skb_shinfo(skb)->frags[f];
len = frag->size;
- map = skb_shinfo(skb)->dma_maps[f + 1];
offset = 0;
while (len) {
- struct e1000_buffer *buffer_info;
+ i++;
+ if (i == tx_ring->count)
+ i = 0;
+
buffer_info = &tx_ring->buffer_info[i];
size = min(len, max_per_txd);
buffer_info->length = size;
buffer_info->time_stamp = jiffies;
- buffer_info->dma = map + offset;
buffer_info->next_to_watch = i;
+ buffer_info->dma = map[f + 1] + offset;
len -= size;
offset += size;
count++;
-
- i++;
- if (i == tx_ring->count)
- i = 0;
}
}
- if (i == 0)
- i = tx_ring->count - 1;
- else
- i--;
-
tx_ring->buffer_info[i].skb = skb;
tx_ring->buffer_info[first].next_to_watch = i;
- smp_wmb();
return count;
}
@@ -4145,20 +4133,20 @@
if (skb->protocol == htons(ETH_P_IP))
tx_flags |= E1000_TX_FLAGS_IPV4;
+ /* if count is 0 then mapping error has occured */
count = e1000_tx_map(adapter, skb, first, max_per_txd, nr_frags, mss);
- if (count < 0) {
- /* handle pci_map_single() error in e1000_tx_map */
+ if (count) {
+ e1000_tx_queue(adapter, tx_flags, count);
+ netdev->trans_start = jiffies;
+ /* Make sure there is space in the ring for the next send. */
+ e1000_maybe_stop_tx(netdev, MAX_SKB_FRAGS + 2);
+
+ } else {
dev_kfree_skb_any(skb);
- return NETDEV_TX_OK;
+ tx_ring->buffer_info[first].time_stamp = 0;
+ tx_ring->next_to_use = first;
}
- e1000_tx_queue(adapter, tx_flags, count);
-
- netdev->trans_start = jiffies;
-
- /* Make sure there is space in the ring for the next send. */
- e1000_maybe_stop_tx(netdev, MAX_SKB_FRAGS + 2);
-
return NETDEV_TX_OK;
}