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authorDoug Berger <opendmb@gmail.com>2020-06-24 18:14:55 -0700
committerDavid S. Miller <davem@davemloft.net>2020-06-24 21:51:03 -0700
commit20d1f2d1b024f6be199a3bedf1578a1d21592bc5 (patch)
treee95e1549bb6733723ae5cdb2eb7f05fb04624762
parentd966d2efb643a8ba925e910bfc10e19c8b018de7 (diff)
downloadlinux-20d1f2d1b024f6be199a3bedf1578a1d21592bc5.tar.gz
net: bcmgenet: use hardware padding of runt frames
When commit 474ea9cafc45 ("net: bcmgenet: correctly pad short packets") added the call to skb_padto() it should have been located before the nr_frags parameter was read since that value could be changed when padding packets with lengths between 55 and 59 bytes (inclusive). The use of a stale nr_frags value can cause corruption of the pad data when tx-scatter-gather is enabled. This corruption of the pad can cause invalid checksum computation when hardware offload of tx-checksum is also enabled. Since the original reason for the padding was corrected by commit 7dd399130efb ("net: bcmgenet: fix skb_len in bcmgenet_xmit_single()") we can remove the software padding all together and make use of hardware padding of short frames as long as the hardware also always appends the FCS value to the frame. Fixes: 474ea9cafc45 ("net: bcmgenet: correctly pad short packets") Signed-off-by: Doug Berger <opendmb@gmail.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/broadcom/genet/bcmgenet.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index c63f01e2bb037..af924a8b885fd 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2042,11 +2042,6 @@ static netdev_tx_t bcmgenet_xmit(struct sk_buff *skb, struct net_device *dev)
goto out;
}
- if (skb_padto(skb, ETH_ZLEN)) {
- ret = NETDEV_TX_OK;
- goto out;
- }
-
/* Retain how many bytes will be sent on the wire, without TSB inserted
* by transmit checksum offload
*/
@@ -2093,6 +2088,9 @@ static netdev_tx_t bcmgenet_xmit(struct sk_buff *skb, struct net_device *dev)
len_stat = (size << DMA_BUFLENGTH_SHIFT) |
(priv->hw_params->qtag_mask << DMA_TX_QTAG_SHIFT);
+ /* Note: if we ever change from DMA_TX_APPEND_CRC below we
+ * will need to restore software padding of "runt" packets
+ */
if (!i) {
len_stat |= DMA_TX_APPEND_CRC | DMA_SOP;
if (skb->ip_summed == CHECKSUM_PARTIAL)