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From: linas@austin.ibm.com (Linas Vepstas)
To: Jeff Garzik <jgarzik@pobox.com>, Andrew Morton <akpm@osdl.org>
Cc: netdev@vger.kernel.org, Florin Malita <fmalita@gmail.com>,
	cbe-oss-dev@ozlabs.org, linuxppc-dev@ozlabs.org
Subject: [PATCH 6/10] spidernet: Don't terminate the RX ring
Date: Tue, 22 May 2007 18:40:59 -0500	[thread overview]
Message-ID: <20070522234059.GE2147@austin.ibm.com> (raw)
In-Reply-To: <20070522230942.GT5921@austin.ibm.com>


There is no real reason to terminate the RX ring; it
doesn't make the operation any smooother, and it does
require an extra sync. So don't do it.

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

----
 drivers/net/spider_net.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

Index: netdev-2.6/drivers/net/spider_net.c
===================================================================
--- netdev-2.6.orig/drivers/net/spider_net.c	2007-05-22 18:03:34.000000000 -0500
+++ netdev-2.6/drivers/net/spider_net.c	2007-05-22 18:03:35.000000000 -0500
@@ -462,13 +462,9 @@ spider_net_prepare_rx_descr(struct spide
 		hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE;
 	} else {
 		hwdescr->buf_addr = buf;
-		hwdescr->next_descr_addr = 0;
 		wmb();
 		hwdescr->dmac_cmd_status = SPIDER_NET_DESCR_CARDOWNED |
 					 SPIDER_NET_DMAC_NOINTR_COMPLETE;
-
-		wmb();
-		descr->prev->hwdescr->next_descr_addr = descr->bus_addr;
 	}
 
 	return 0;
@@ -557,12 +553,16 @@ spider_net_refill_rx_chain(struct spider
 static int
 spider_net_alloc_rx_skbs(struct spider_net_card *card)
 {
-	int result;
-	struct spider_net_descr_chain *chain;
+	struct spider_net_descr_chain *chain = &card->rx_chain;
+	struct spider_net_descr *start= chain->tail;
+	struct spider_net_descr *descr = start;
 
-	result = -ENOMEM;
+	/* Link up the hardware chain pointers */
+	do {
+		descr->prev->hwdescr->next_descr_addr = descr->bus_addr;
+		descr = descr->next;
+	} while (descr != start);
 
-	chain = &card->rx_chain;
 	/* Put at least one buffer into the chain. if this fails,
 	 * we've got a problem. If not, spider_net_refill_rx_chain
 	 * will do the rest at the end of this function. */
@@ -579,7 +579,7 @@ spider_net_alloc_rx_skbs(struct spider_n
 
 error:
 	spider_net_free_rx_chain_contents(card);
-	return result;
+	return -ENOMEM;
 }
 
 /**

  parent reply	other threads:[~2007-05-22 23:40 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-22 23:09 [PATCH 1/10] spidernet: skb used after netif_receive_skb Linas Vepstas
2007-05-22 23:13 ` [PATCH 2/10] spidernet: beautify error messages Linas Vepstas
2007-05-24 21:27   ` Jeff Garzik
2007-05-22 23:21 ` [PATCH 3/10] spidernet: move a block of code around Linas Vepstas
2007-05-22 23:36 ` [PATCH 4/10] spidernet: zero out a pointer Linas Vepstas
2007-05-22 23:39 ` [PATCH 5/10] spidernet: null out skb pointer after its been used Linas Vepstas
2007-05-22 23:40 ` Linas Vepstas [this message]
2007-05-22 23:42 ` [PATCH 7/10] spidernet: enhance the dump routine Linas Vepstas
2007-05-22 23:45 ` [PATCH 8/10] spidernet: reset the card when an rxramfull is seen Linas Vepstas
2007-05-22 23:47 ` [PATCH 9/10] spidernet: service TX later Linas Vepstas
2007-05-22 23:52 ` [PATCH 10/10] spidernet: increase the NAPI weight Linas Vepstas
2007-05-24 21:25 ` [PATCH 1/10] spidernet: skb used after netif_receive_skb Jeff Garzik

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