Re: [PATCH net-next] bnx2x: fix GRO parameters

[Eric Dumazet <eric.dumazet@gmail.com>]

On Wed, 2013-01-16 at 09:01 +0200, Yuval Mintz wrote:
> > -static u16 bnx2x_set_lro_mss(struct bnx2x *bp, u16 parsing_flags,
> > -			     u16 len_on_bd)
> > +static void bnx2x_set_gro_params(struct sk_buff *skb, struct bnx2x *bp,
> > +				 u16 parsing_flags, u16 len_on_bd,
> > +				 unsigned int pkt_len)
> 
> This is purely semantic, but our convention is for `struct bnx2x' to be
> the first argument in our functions.
> 
> >  {
> >  	/*
> > -	 * TPA arrgregation won't have either IP options or TCP options
> > +	 * TPA aggregation won't have either IP options or TCP options
> >  	 * other than timestamp or IPv6 extension headers.
> >  	 */
> >  	u16 hdrs_len = ETH_HLEN + sizeof(struct tcphdr);
> 
> TPA_MODE_LRO indicates that an LRO aggregation was made by our FW. It seems
> like your patch  eliminates the difference in configuration between the two
> (GRO and LRO)
> 

Thats the case, since you call GRO functions even if 'LRO ' is ON

I specifically had to remove the tests you guys do.

> perhaps instead we should do something like:
> 
> + static void bnx2x_set_lro_params(struct bnx2x *bp, struct sk_buff *skb,
> + 				   u16 parsing_flags, u16 len_on_bd,
> + 				   unsigned int pkt_len,
> +				   bnx2x_tpa_mode_t mode)
> 
> And arrange its suggested code so that only gso_size will be set for LRO.
> 

I fail to understand why adding a conditional would change something.

Setting it is needed for GRO as well.

> >  
> >  	if (GET_FLAG(parsing_flags, PARSING_FLAGS_OVER_ETHERNET_PROTOCOL) ==
> > -	    PRS_FLAG_OVERETH_IPV6)
> > +	    PRS_FLAG_OVERETH_IPV6) {
> >  		hdrs_len += sizeof(struct ipv6hdr);
> > -	else /* IPv4 */
> > +		skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
> > +	} else {
> >  		hdrs_len += sizeof(struct iphdr);
> > -
> > +		skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
> > +	}
> >  
> 
> 
> 
> >  #ifdef BNX2X_STOP_ON_ERROR
> > @@ -651,7 +655,7 @@ static void bnx2x_gro_receive(struct bnx2x *bp, struct bnx2x_fastpath *fp,
> >  			       struct sk_buff *skb)
> >  {
> >  #ifdef CONFIG_INET
> > -	if (fp->mode == TPA_MODE_GRO && skb_shinfo(skb)->gso_size) {
> > +	if (skb_shinfo(skb)->gso_size) {
> 
> This also seems like an incorrect removal, as TPA_MODE_LRO is (again)
> a feasible option, and we wouldn't want the a `gro_complete' here.
> 


Problem is : You call GRO functions, faking a GRO packet.

You must therefore exactly present same attributes in skb than after a
true software GRO step.

I did my tests booting a standard driver, that is with LRO on.