From mboxrd@z Thu Jan 1 00:00:00 1970 From: linas@austin.ibm.com (Linas Vepstas) Subject: [PATCH 14/14] Spidernet Rework RX linked list Date: Wed, 13 Dec 2006 15:25:05 -0600 Message-ID: <20061213212505.GN1915@austin.ibm.com> References: <20061213210010.GR4329@austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, linuxppc-dev@ozlabs.org, jgarzik@pobox.com, Christoph Hellwig , Ishizaki Kou , Jens Osterkamp , James K Lewis , Arnd Bergmann Return-path: Received: from e6.ny.us.ibm.com ([32.97.182.146]:46913 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751080AbWLMVZI (ORCPT ); Wed, 13 Dec 2006 16:25:08 -0500 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e6.ny.us.ibm.com (8.13.8/8.12.11) with ESMTP id kBDLPYUj005473 for ; Wed, 13 Dec 2006 16:25:34 -0500 Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay02.pok.ibm.com (8.13.6/8.13.6/NCO v8.1.1) with ESMTP id kBDLP7UF270250 for ; Wed, 13 Dec 2006 16:25:07 -0500 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id kBDLP5UY032148 for ; Wed, 13 Dec 2006 16:25:07 -0500 To: Andrew Morton Content-Disposition: inline In-Reply-To: <20061213210010.GR4329@austin.ibm.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Make the hardware perceive the RX descriptor ring as a null-terminated linked list, instead of a circular ring. Signed-off-by: Linas Vepstas Cc: James K Lewis Cc: Arnd Bergmann ---- drivers/net/spider_net.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) Index: linux-2.6.19-git7/drivers/net/spider_net.c =================================================================== --- linux-2.6.19-git7.orig/drivers/net/spider_net.c 2006-12-13 14:32:13.000000000 -0600 +++ linux-2.6.19-git7/drivers/net/spider_net.c 2006-12-13 14:33:21.000000000 -0600 @@ -419,9 +419,13 @@ spider_net_prepare_rx_descr(struct spide card->spider_stats.rx_iommu_map_error++; descr->dmac_cmd_status = SPIDER_NET_DESCR_NOT_IN_USE; } else { + descr->next_descr_addr = 0; wmb(); descr->dmac_cmd_status = SPIDER_NET_DESCR_CARDOWNED | SPIDER_NET_DMAC_NOINTR_COMPLETE; + + wmb(); + descr->prev->next_descr_addr = descr->bus_addr; } return 0; @@ -1650,7 +1654,6 @@ int spider_net_open(struct net_device *netdev) { struct spider_net_card *card = netdev_priv(netdev); - struct spider_net_descr *descr; int result; result = spider_net_init_chain(card, &card->tx_chain); @@ -1662,13 +1665,6 @@ spider_net_open(struct net_device *netde if (result) goto alloc_rx_failed; - /* Make a ring of of bus addresses */ - descr = card->rx_chain.ring; - do { - descr->next_descr_addr = descr->next->bus_addr; - descr = descr->next; - } while (descr != card->rx_chain.ring); - /* Allocate rx skbs */ if (spider_net_alloc_rx_skbs(card)) goto alloc_skbs_failed;