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[PATCH] sky2: optimize receive restart

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When the driver handles multiple packets per NAPI poll, it is
better to reload the receive ring, then tell the hardware. Otherwise,
under packet storm with flow control, the driver/hardware will degrade
down to one packet getting through per pause-exchange.

Likewise on transmit, don't wakeup until a little more than minimum
ring space is available.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Stephen Hemminger 2006-07-12 15:23:48 -07:00 committed by Jeff Garzik
parent afa195da45
commit 22e1170310
1 changed files with 22 additions and 5 deletions
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27
drivers/net/sky2.c
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@ -65,6 +65,7 @@
#define RX_MAX_PENDING (RX_LE_SIZE/2 - 2)
#define RX_DEF_PENDING RX_MAX_PENDING
#define RX_SKB_ALIGN 8
#define RX_BUF_WRITE 16
#define TX_RING_SIZE 512
#define TX_DEF_PENDING (TX_RING_SIZE - 1)
@ -1390,7 +1391,7 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done)
}
sky2->tx_cons = put;
if (tx_avail(sky2) > MAX_SKB_TX_LE)
if (tx_avail(sky2) > MAX_SKB_TX_LE + 4)
netif_wake_queue(dev);
}
@ -1889,9 +1890,6 @@ resubmit:
re->skb->ip_summed = CHECKSUM_NONE;
sky2_rx_add(sky2, re->mapaddr);
/* Tell receiver about new buffers. */
sky2_put_idx(sky2->hw, rxqaddr[sky2->port], sky2->rx_put);
return skb;
oversize:
@ -1938,7 +1936,9 @@ static inline int sky2_more_work(const struct sky2_hw *hw)
/* Process status response ring */
static int sky2_status_intr(struct sky2_hw *hw, int to_do)
{
struct sky2_port *sky2;
int work_done = 0;
unsigned buf_write[2] = { 0, 0 };
u16 hwidx = sky2_read16(hw, STAT_PUT_IDX);
rmb();
@ -1946,7 +1946,6 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do)
while (hw->st_idx != hwidx) {
struct sky2_status_le *le = hw->st_le + hw->st_idx;
struct net_device *dev;
struct sky2_port *sky2;
struct sk_buff *skb;
u32 status;
u16 length;
@ -1979,6 +1978,14 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do)
#endif
netif_receive_skb(skb);
/* Update receiver after 16 frames */
if (++buf_write[le->link] == RX_BUF_WRITE) {
sky2_put_idx(hw, rxqaddr[le->link],
sky2->rx_put);
buf_write[le->link] = 0;
}
/* Stop after net poll weight */
if (++work_done >= to_do)
goto exit_loop;
break;
@ -2017,6 +2024,16 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do)
}
exit_loop:
if (buf_write[0]) {
sky2 = netdev_priv(hw->dev[0]);
sky2_put_idx(hw, Q_R1, sky2->rx_put);
}
if (buf_write[1]) {
sky2 = netdev_priv(hw->dev[1]);
sky2_put_idx(hw, Q_R2, sky2->rx_put);
}
return work_done;
}