netdev - [PATCH 5/15] spidernet: turn off descriptor chain end interrupt.

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Date:	Mon, 11 Jun 2007 13:29:03 -0500
From:	linas@...tin.ibm.com (Linas Vepstas)
To:	Jeff Garzik <jeff@...zik.org>
Cc:	Michael Ellerman <michael@...erman.id.au>, netdev@...r.kernel.org,
	cbe-oss-dev@...abs.org
Subject: [PATCH 5/15] spidernet: turn off descriptor chain end interrupt.


At some point, the transmit descriptor chain end interrupt (TXDCEINT)
was turned on. This is a mistake; and it damages small packet
transmit performance, as it results in a huge storm of interrupts.  
Turn it off.

Signed-off-by: Linas Vepstas <linas@...tin.ibm.com>

----
 drivers/net/spider_net.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6.22-rc1/drivers/net/spider_net.h
===================================================================
--- linux-2.6.22-rc1.orig/drivers/net/spider_net.h	2007-06-08 17:40:02.000000000 -0500
+++ linux-2.6.22-rc1/drivers/net/spider_net.h	2007-06-08 17:40:05.000000000 -0500
@@ -222,6 +222,7 @@ extern char spider_net_driver_name[];
 #define SPIDER_NET_GDTBSTA             0x00000300
 #define SPIDER_NET_GDTDCEIDIS          0x00000002
 #define SPIDER_NET_DMA_TX_VALUE        SPIDER_NET_TX_DMA_EN | \
+                                       SPIDER_NET_GDTDCEIDIS | \
                                        SPIDER_NET_GDTBSTA
 
 #define SPIDER_NET_DMA_TX_FEND_VALUE	0x00030003
@@ -332,8 +333,7 @@ enum spider_net_int2_status {
 	SPIDER_NET_GRISPDNGINT
 };
 
-#define SPIDER_NET_TXINT	( (1 << SPIDER_NET_GDTFDCINT) | \
-                             (1 << SPIDER_NET_GDTDCEINT) )
+#define SPIDER_NET_TXINT	(1 << SPIDER_NET_GDTFDCINT)
 
 /* We rely on flagged descriptor interrupts */
 #define SPIDER_NET_RXINT	( (1 << SPIDER_NET_GDAFDCINT) )
-
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