From mboxrd@z Thu Jan 1 00:00:00 1970 From: linas@austin.ibm.com (Linas Vepstas) Subject: [PATCH 6/10] spidernet: Don't terminate the RX ring Date: Tue, 22 May 2007 18:40:59 -0500 Message-ID: <20070522234059.GE2147@austin.ibm.com> References: <20070522230942.GT5921@austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: cbe-oss-dev@ozlabs.org, netdev@vger.kernel.org, linuxppc-dev@ozlabs.org, Florin Malita To: Jeff Garzik , Andrew Morton Return-path: Received: from e1.ny.us.ibm.com ([32.97.182.141]:55358 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755821AbXEVXlB (ORCPT ); Tue, 22 May 2007 19:41:01 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e1.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id l4MNf0qO007739 for ; Tue, 22 May 2007 19:41:00 -0400 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.3) with ESMTP id l4MNf0ce398360 for ; Tue, 22 May 2007 19:41:00 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l4MNex8N015347 for ; Tue, 22 May 2007 19:41:00 -0400 Content-Disposition: inline In-Reply-To: <20070522230942.GT5921@austin.ibm.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 ---- 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; } /**