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Date: Thu, 13 Dec 2007 09:35:54 -0800
From: Stephen Hemminger <shemminger@...ux-foundation.org>
To: "David S. Miller" <davem@...emloft.net>,
Jeff Garzik <jgarzik@...ox.com>
Cc: netdev@...r.kernel.org, kristjan <kristjan.ugrin@...il.com>
Subject: [PATCH 2/2] tulip: hardware mitigation simplify
The hardware mitigation in tulip can be simpified.
1. The budget with new NAPI will always be less than RX_RING_SIZE
because RX_RING_SIZE is 128 and weight is 16.
2. The received counter is redundunt, just use the work_done value.
3. Only one value is used from the mit_table[]
Signed-off-by: Stephen Hemminger <shemminger@...ux-foundation.org>
---
This can wait for 2.6.25
--- a/drivers/net/tulip/interrupt.c 2007-12-13 09:26:35.000000000 -0800
+++ b/drivers/net/tulip/interrupt.c 2007-12-13 09:27:29.000000000 -0800
@@ -21,45 +21,6 @@
int tulip_rx_copybreak;
unsigned int tulip_max_interrupt_work;
-#ifdef CONFIG_TULIP_NAPI_HW_MITIGATION
-#define MIT_SIZE 15
-#define MIT_TABLE 15 /* We use 0 or max */
-
-static unsigned int mit_table[MIT_SIZE+1] =
-{
- /* CRS11 21143 hardware Mitigation Control Interrupt
- We use only RX mitigation we other techniques for
- TX intr. mitigation.
-
- 31 Cycle Size (timer control)
- 30:27 TX timer in 16 * Cycle size
- 26:24 TX No pkts before Int.
- 23:20 RX timer in Cycle size
- 19:17 RX No pkts before Int.
- 16 Continues Mode (CM)
- */
-
- 0x0, /* IM disabled */
- 0x80150000, /* RX time = 1, RX pkts = 2, CM = 1 */
- 0x80150000,
- 0x80270000,
- 0x80370000,
- 0x80490000,
- 0x80590000,
- 0x80690000,
- 0x807B0000,
- 0x808B0000,
- 0x809D0000,
- 0x80AD0000,
- 0x80BD0000,
- 0x80CF0000,
- 0x80DF0000,
-// 0x80FF0000 /* RX time = 16, RX pkts = 7, CM = 1 */
- 0x80F10000 /* RX time = 16, RX pkts = 0, CM = 1 */
-};
-#endif
-
-
int tulip_refill_rx(struct net_device *dev)
{
struct tulip_private *tp = netdev_priv(dev);
@@ -113,21 +74,10 @@ int tulip_poll(struct napi_struct *napi,
struct net_device *dev = tp->dev;
int entry = tp->cur_rx % RX_RING_SIZE;
int work_done = 0;
-#ifdef CONFIG_TULIP_NAPI_HW_MITIGATION
- int received = 0;
-#endif
if (!netif_running(dev))
goto done;
-#ifdef CONFIG_TULIP_NAPI_HW_MITIGATION
-
-/* that one buffer is needed for mit activation; or might be a
- bug in the ring buffer code; check later -- JHS*/
-
- if (budget >=RX_RING_SIZE) budget--;
-#endif
-
if (tulip_debug > 4)
printk(KERN_DEBUG " In tulip_rx(), entry %d %8.8x.\n", entry,
tp->rx_ring[entry].status);
@@ -239,9 +189,6 @@ int tulip_poll(struct napi_struct *napi,
tp->stats.rx_packets++;
tp->stats.rx_bytes += pkt_len;
}
-#ifdef CONFIG_TULIP_NAPI_HW_MITIGATION
- received++;
-#endif
entry = (++tp->cur_rx) % RX_RING_SIZE;
if (tp->cur_rx - tp->dirty_rx > RX_RING_SIZE/4)
@@ -279,14 +226,14 @@ done:
ON: More then 1 pkt received (per intr.) OR we are dropping
OFF: Only 1 pkt received
- Note. We only use min and max (0, 15) settings from mit_table */
-
+ Note. We only use max or min values for mit */
if( tp->flags & HAS_INTR_MITIGATION) {
- if( received > 1 ) {
+ if( work_done > 1 ) {
if( ! tp->mit_on ) {
tp->mit_on = 1;
- iowrite32(mit_table[MIT_TABLE], tp->base_addr + CSR11);
+ /* RX time = 16, RX pkts = 0, CM = 1 */
+ iowrite32(0x80F10000, tp->base_addr + CSR11);
}
}
else {
--
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