| Message ID | 1408474371-19509-3-git-send-email-bpoirier@suse.de |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 7022f6d..27e2701 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -12328,7 +12328,7 @@ static int tg3_set_ringparam(struct net_device *dev, struct ethtool_ringparam *e if ((ering->rx_pending > tp->rx_std_ring_mask) || (ering->rx_jumbo_pending > tp->rx_jmb_ring_mask) || (ering->tx_pending > TG3_TX_RING_SIZE - 1) || - (ering->tx_pending <= MAX_SKB_FRAGS)) + (ering->tx_pending <= MAX_SKB_FRAGS + 1)) return -EINVAL; if (netif_running(dev)) {
The rest of the driver assumes at least one free descriptor in the tx ring. Therefore, since an skb with max frags takes up (MAX_SKB_FRAGS + 1) descriptors, tx_pending must be > (MAX_SKB_FRAGS + 1). Signed-off-by: Benjamin Poirier <bpoirier@suse.de> --- Currently, it is possible to set tx_pending = MAX_SKB_FRAGS + 1. This leads to a netdev watchdog tx timeout. Depending on whether the previous patches in this series are applied or not, the timeout happens as soon as tx_pending is updated or after an skb with max frags is submitted for transmission. I reproduced this bug using the same approach explained in patch 1. The bug reproduces with tx_pending = 18 --- drivers/net/ethernet/broadcom/tg3.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)