mlx5: fix bug reading rss_hash_type from CQE

Masks for extracting part of the Completion Queue Entry (CQE)
field rss_hash_type was swapped, namely CQE_RSS_HTYPE_IP and
CQE_RSS_HTYPE_L4.

The bug resulted in setting skb->l4_hash, even-though the
rss_hash_type indicated that hash was NOT computed over the
L4 (UDP or TCP) part of the packet.

Added comments from the datasheet, to make it more clear what
these masks are selecting.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index dd9a263ed368d5476b06a3464bbfada0436cf6e2..a940ec6a046cfd0dc8c3016226c71ea9e2c343e5 100644 (file)
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -787,8 +787,14 @@ enum {
 };
 
 enum {
-       CQE_RSS_HTYPE_IP        = 0x3 << 6,
-       CQE_RSS_HTYPE_L4        = 0x3 << 2,
+       CQE_RSS_HTYPE_IP        = 0x3 << 2,
+       /* cqe->rss_hash_type[3:2] - IP destination selected for hash
+        * (00 = none,  01 = IPv4, 10 = IPv6, 11 = Reserved)
+        */
+       CQE_RSS_HTYPE_L4        = 0x3 << 6,
+       /* cqe->rss_hash_type[7:6] - L4 destination selected for hash
+        * (00 = none, 01 = TCP. 10 = UDP, 11 = IPSEC.SPI
+        */
 };
 
 enum {