net/sonic: Remove redundant next_tx variable

The eol_tx variable is the one that matters to the tx algorithm because
packets are always placed at the end of the list. The next_tx variable
just confuses things so remove it.

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 c066510..9ecdd67 100644 (file)
--- a/drivers/net/ethernet/natsemi/sonic.c
+++ b/drivers/net/ethernet/natsemi/sonic.c
@@ -300,7 +300,7 @@ static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
 
        spin_lock_irqsave(&lp->lock, flags);
 
-       entry = lp->next_tx;
+       entry = (lp->eol_tx + 1) & SONIC_TDS_MASK;
 
        sonic_tda_put(dev, entry, SONIC_TD_STATUS, 0);       /* clear status */
        sonic_tda_put(dev, entry, SONIC_TD_FRAG_COUNT, 1);   /* single fragment */
@@ -321,8 +321,8 @@ static int sonic_send_packet(struct sk_buff *skb, struct net_device *dev)
                                  sonic_tda_get(dev, lp->eol_tx, SONIC_TD_LINK) & ~SONIC_EOL);
        lp->eol_tx = entry;
 
-       lp->next_tx = (entry + 1) & SONIC_TDS_MASK;
-       if (lp->tx_skb[lp->next_tx] != NULL) {
+       entry = (entry + 1) & SONIC_TDS_MASK;
+       if (lp->tx_skb[entry]) {
                /* The ring is full, the ISR has yet to process the next TD. */
                netif_dbg(lp, tx_queued, dev, "%s: stopping queue\n", __func__);
                netif_stop_queue(dev);
@@ -811,7 +811,7 @@ static int sonic_init(struct net_device *dev)
 
        SONIC_WRITE(SONIC_UTDA, lp->tda_laddr >> 16);
        SONIC_WRITE(SONIC_CTDA, lp->tda_laddr & 0xffff);
-       lp->cur_tx = lp->next_tx = 0;
+       lp->cur_tx = 0;
        lp->eol_tx = SONIC_NUM_TDS - 1;
 
        /*

diff --git a/drivers/net/ethernet/natsemi/sonic.h b/drivers/net/ethernet/natsemi/sonic.h
index 053f12f..3cbb62c 100644 (file)
--- a/drivers/net/ethernet/natsemi/sonic.h
+++ b/drivers/net/ethernet/natsemi/sonic.h
@@ -321,7 +321,6 @@ struct sonic_local {
        unsigned int cur_tx;           /* first unacked transmit packet */
        unsigned int eol_rx;
        unsigned int eol_tx;           /* last unacked transmit packet */
-       unsigned int next_tx;          /* next free TD */
        int msg_enable;
        struct device *device;         /* generic device */
        struct net_device_stats stats;