These rules must be followed when accessing the TX descriptor:
1. A TX descriptor is "cleanable" only when its value is non-zero
and the owner bit is set to "software"
2. A TX descriptor is "writable" only when its value is zero regardless
the edotr mask.
Fixes: 52c0cae87465 ("ftgmac100: Remove tx descriptor accessors")
Signed-off-by: Dylan Hung <dylan_h...@aspeedtech.com>
Signed-off-by: Joel Stanley <j...@jms.id.au>
---
drivers/net/ethernet/faraday/ftgmac100.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/net/ethernet/faraday/ftgmac100.c
b/drivers/net/ethernet/faraday/ftgmac100.c
index 00024dd41147..7cacbe4aecb7 100644
--- a/drivers/net/ethernet/faraday/ftgmac100.c
+++ b/drivers/net/ethernet/faraday/ftgmac100.c
@@ -647,6 +647,9 @@ static bool ftgmac100_tx_complete_packet(struct ftgmac100
*priv)
if (ctl_stat & FTGMAC100_TXDES0_TXDMA_OWN)
return false;
+ if ((ctl_stat & ~(priv->txdes0_edotr_mask)) == 0)
+ return false;
+
skb = priv->tx_skbs[pointer];
netdev->stats.tx_packets++;
netdev->stats.tx_bytes += skb->len;
@@ -756,6 +759,9 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff
*skb,
pointer = priv->tx_pointer;
txdes = first = &priv->txdes[pointer];
+ if (le32_to_cpu(txdes->txdes0) & ~priv->txdes0_edotr_mask)
+ goto drop;
+
/* Setup it up with the packet head. Don't write the head to the
* ring just yet
*/
@@ -787,6 +793,10 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct
sk_buff *skb,
/* Setup descriptor */
priv->tx_skbs[pointer] = skb;
txdes = &priv->txdes[pointer];
+
+ if (le32_to_cpu(txdes->txdes0) & ~priv->txdes0_edotr_mask)
+ goto dma_err;
+
ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer);
ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN;
ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);
--
2.17.1
