>-----Original Message----- >From: Lennert Buytenhek [mailto:buytenh@xxxxxxxxxxxxxx] >Sent: Thursday, June 10, 2010 9:44 AM >To: Saeed Bishara >Cc: linux-net@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx >Subject: Re: [PATCH 1/2 v2] mv643xx_eth: use sw csum for big packets > >On Wed, Jun 09, 2010 at 11:51:23AM +0300, Saeed Bishara wrote: > >> diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c >> index e345ec8..2d0e06b 100644 >> --- a/drivers/net/mv643xx_eth.c >> +++ b/drivers/net/mv643xx_eth.c >> @@ -289,6 +289,7 @@ struct mv643xx_eth_shared_private { >> unsigned int t_clk; >> int extended_rx_coal_limit; >> int tx_bw_control; >> + int tx_csum_limit; >> }; >> >> #define TX_BW_CONTROL_ABSENT 0 >> @@ -782,7 +783,8 @@ static int txq_submit_skb(struct >tx_queue *txq, struct sk_buff *skb) >> skb->protocol != htons(ETH_P_8021Q)); >> >> tag_bytes = (void *)ip_hdr(skb) - (void >*)skb->data - ETH_HLEN; >> - if (unlikely(tag_bytes & ~12)) { >> + if (unlikely(tag_bytes & ~12) || >> + skb->len > mp->shared->tx_csum_limit) { > >Please line up skb->len with unlikely() on the line above it. > > >> @@ -2666,6 +2668,9 @@ static int >mv643xx_eth_shared_probe(struct platform_device *pdev) >> * Detect hardware parameters. >> */ >> msp->t_clk = (pd != NULL && pd->t_clk != 0) ? pd->t_clk >: 133000000; >> + msp->tx_csum_limit = pd->tx_csum_limit ? >pd->tx_csum_limit : 9 * 1024; >> + /* add header count so we can compare against skb->len */ >> + msp->tx_csum_limit += ETH_HLEN; >> infer_hw_params(msp); > >Is the limit 9 * 1024 + 14 for the whole packet, or 9 * 1024 for the IP >part? the limit is for the IP part, but I thought that adding the header length, then comparing agains skb->len will be the same. What do you suggest? > >I.e. what happens if skb->len is 9 * 1024 + 15, but there is one VLAN >tag present -- will the hardware be able to do the checksum offload or >not? >-- To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
