On 19/06/2017 8:04 PM, Davide Caratti wrote:
hello Tariq,
On Sun, 2017-06-18 at 14:10 +0300, Tariq Toukan wrote:
@@ -624,12 +632,13 @@ static int check_csum(struct mlx4_cqe *cqe, struct 
sk_buff *skb, void *va,
                hdr += sizeof(struct vlan_hdr);
        }
- if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV4))
-             get_fixed_ipv4_csum(hw_checksum, skb, hdr);
+     if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV4)) &&
+         (unlikely(get_fixed_ipv4_csum(hw_checksum, skb, hdr))))

No! The lazy evaluation trick is wrong here.
This way you'll end up going almost always to the else (ipv6) for the
wrong reason.

you are right! thanks for spotting this.

+             return -1;
    #if IS_ENABLED(CONFIG_IPV6)
-     else if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV6))
-             if (unlikely(get_fixed_ipv6_csum(hw_checksum, skb, hdr)))
-                     return -1;
+     else if ((cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV6)) &&
+              (unlikely(get_fixed_ipv6_csum(hw_checksum, skb, hdr))))
+             return -1;

Let's not change this, might cause future bugs, similarly to the one above.
    #endif
        return 0;
    }

maybe we can avoid adding braces, remove that 'else' keyword and the nested 
'if',
thus saving one line, given that check_csum() returns the same set of values as
get_fixed_ipv{4,6}_checksum(), with the same meaning (-1 => go with 
CHECKSUM_NONE,
0 => go with CHECKSUM_COMPLETE).

Yeah this sounds good.

---- >8 ----
@@ -625,11 +633,10 @@ static int check_csum(struct mlx4_cqe *cqe, struct 
sk_buff *skb, void *va,
        }
if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV4))
-               get_fixed_ipv4_csum(hw_checksum, skb, hdr);
+               return get_fixed_ipv4_csum(hw_checksum, skb, hdr);
  #if IS_ENABLED(CONFIG_IPV6)
-       else if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV6))
-               if (unlikely(get_fixed_ipv6_csum(hw_checksum, skb, hdr)))
-                       return -1;
+       if (cqe->status & cpu_to_be16(MLX4_CQE_STATUS_IPV6))
+               return get_fixed_ipv6_csum(hw_checksum, skb, hdr);
  #endif
        return 0;
  }
---- 8< ----

Looks good to me.


I will test and repost a v2 with this modification, unless you have any
objections. Thank you in advance!
regards
--
davide



Thank you Davide.

Regards,
Tariq

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