From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH alt] sky2: transmit ring accounting Date: Mon, 14 Sep 2009 09:12:55 -0700 Message-ID: <20090914091255.2cda7d24@nehalam> References: <4AAD7B3D.7010403@ring3k.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Mike McCormack , David Miller Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:43163 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751276AbZINQNl (ORCPT ); Mon, 14 Sep 2009 12:13:41 -0400 In-Reply-To: <4AAD7B3D.7010403@ring3k.org> Sender: netdev-owner@vger.kernel.org List-ID: Be more accurate about number of transmit list elements required. Signed-off-by: Stephen Hemminger --- Note: this is an optimization, the old code guaranteed more space than necessary (MAX_SKB_TX_LE was always bigger than needed). --- a/drivers/net/sky2.c 2009-09-14 08:45:55.730729606 -0700 +++ b/drivers/net/sky2.c 2009-09-14 09:09:42.395712810 -0700 @@ -65,8 +65,8 @@ #define RX_DEF_PENDING RX_MAX_PENDING /* This is the worst case number of transmit list elements for a single skb: - VLAN + TSO + CKSUM + Data + skb_frags * DMA */ -#define MAX_SKB_TX_LE (4 + (sizeof(dma_addr_t)/sizeof(u32))*MAX_SKB_FRAGS) + VLAN:GSO + CKSUM + Data + skb_frags * DMA */ +#define MAX_SKB_TX_LE (2 + (sizeof(dma_addr_t)/sizeof(u32))*(MAX_SKB_FRAGS+1)) #define TX_MIN_PENDING (MAX_SKB_TX_LE+1) #define TX_MAX_PENDING 4096 #define TX_DEF_PENDING 127 @@ -1567,11 +1567,13 @@ static unsigned tx_le_req(const struct s { unsigned count; - count = sizeof(dma_addr_t) / sizeof(u32); - count += skb_shinfo(skb)->nr_frags * count; + count = (skb_shinfo(skb)->nr_frags + 1) + * (sizeof(dma_addr_t) / sizeof(u32)); if (skb_is_gso(skb)) ++count; + else if (sizeof(dma_addr_t) == sizeof(u32)) + ++count; /* possible vlan */ if (skb->ip_summed == CHECKSUM_PARTIAL) ++count;