[PATCH] sky2: transmit complete index optimization

Change transmit complete handling to use the status values
in the poll list because they are in-cache, rather than reading
non-cached memory for chips status.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 8dfd27d..ff6557d 100644 (file)
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1274,7 +1274,7 @@ out:
 }
 
 /* Cleanup all untransmitted buffers, assume transmitter not running */
-static inline void sky2_tx_clean(struct sky2_port *sky2)
+static void sky2_tx_clean(struct sky2_port *sky2)
 {
        sky2_tx_complete(sky2, sky2->tx_prod);
 }
@@ -1714,14 +1714,16 @@ error:
 /*
  * Check for transmit complete
  */
-static inline void sky2_tx_check(struct sky2_hw *hw, int port)
-{
-       struct net_device *dev = hw->dev[port];
+#define TX_NO_STATUS   0xffff
 
-       if (dev && netif_running(dev)) {
-               sky2_tx_complete(netdev_priv(dev),
-                                sky2_read16(hw, port == 0
-                                            ? STAT_TXA1_RIDX : STAT_TXA2_RIDX));
+static inline void sky2_tx_check(struct sky2_hw *hw, int port, u16 last)
+{
+       if (last != TX_NO_STATUS) {
+               struct net_device *dev = hw->dev[port];
+               if (dev && netif_running(dev)) {
+                       struct sky2_port *sky2 = netdev_priv(dev);
+                       sky2_tx_complete(sky2, last);
+               }
        }
 }
 
@@ -1735,6 +1737,7 @@ static int sky2_poll(struct net_device *dev0, int *budget)
        unsigned int to_do = min(dev0->quota, *budget);
        unsigned int work_done = 0;
        u16 hwidx;
+       u16 tx_done[2] = { TX_NO_STATUS, TX_NO_STATUS };
 
        sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
        hwidx = sky2_read16(hw, STAT_PUT_IDX);
@@ -1806,7 +1809,10 @@ static int sky2_poll(struct net_device *dev0, int *budget)
                        break;
 
                case OP_TXINDEXLE:
-                       /* pick up transmit status later */
+                       /* TX index reports status for both ports */
+                       tx_done[0] = status & 0xffff;
+                       tx_done[1] = ((status >> 24) & 0xff)
+                               | (u16)(length & 0xf) << 8;
                        break;
 
                default:
@@ -1818,16 +1824,13 @@ static int sky2_poll(struct net_device *dev0, int *budget)
        }
 
 exit_loop:
-       sky2_tx_check(hw, 0);
-       sky2_tx_check(hw, 1);
-
        mmiowb();
 
+       sky2_tx_check(hw, 0, tx_done[0]);
+       sky2_tx_check(hw, 1, tx_done[1]);
+
        if (work_done < to_do) {
-               /*
-                * Another chip workaround, need to restart TX timer if status
-                * LE was handled. WA_DEV_43_418
-                */
+               /* need to restart TX timer */
                if (is_ec_a1(hw)) {
                        sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP);
                        sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);