From: <akepner@sgi.com>
Returning from tg3_poll() without flushing the PIO write which reenables
interrupts can result in lower cpu utilization and higher throughput. So
use a memory barrier, mmiowb(), instead of flushing the write with a PIO
read.
Signed-off-by: Arthur Kepner <akepner@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/drivers/net/tg3.c | 16 +++++++++++++++-
1 files changed, 15 insertions(+), 1 deletion(-)
diff -puN drivers/net/tg3.c~use-mmiowb-in-tg3_poll drivers/net/tg3.c
--- 25/drivers/net/tg3.c~use-mmiowb-in-tg3_poll 2004-10-28 01:13:54.785677656 -0700
+++ 25-akpm/drivers/net/tg3.c 2004-10-28 01:13:54.800675376 -0700
@@ -420,6 +420,20 @@ static void tg3_enable_ints(struct tg3 *
tg3_cond_int(tp);
}
+/* tg3_restart_ints
+ * similar to tg3_enable_ints, but it can return without flushing the
+ * PIO write which reenables interrupts
+ */
+static void tg3_restart_ints(struct tg3 *tp)
+{
+ tw32(TG3PCI_MISC_HOST_CTRL,
+ (tp->misc_host_ctrl & ~MISC_HOST_CTRL_MASK_PCI_INT));
+ tw32_mailbox(MAILBOX_INTERRUPT_0 + TG3_64BIT_REG_LOW, 0x00000000);
+ mmiowb();
+
+ tg3_cond_int(tp);
+}
+
static inline void tg3_netif_stop(struct tg3 *tp)
{
netif_poll_disable(tp->dev);
@@ -2790,7 +2804,7 @@ static int tg3_poll(struct net_device *n
if (done) {
spin_lock_irqsave(&tp->lock, flags);
__netif_rx_complete(netdev);
- tg3_enable_ints(tp);
+ tg3_restart_ints(tp);
spin_unlock_irqrestore(&tp->lock, flags);
}
_