i40e: remove CRC size from byte counters

This patch removes the crc bytes from byte counter statistics.

Doing so fixes a bug that CRC bytes were included on TX but not
on RX, causing mismatch of bytes received / sent.

Fixes: 9aace75fc82e ("i40e: fix statistics")

Reported-by: Weichun Chen <weichunx.chen@intel.com>
Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 2c51a0b..6cf99dc 100644 (file)
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -1870,6 +1870,7 @@ i40e_read_stats_registers(struct i40e_pf *pf, struct i40e_hw *hw)
        unsigned int i;
        struct i40e_hw_port_stats *ns = &pf->stats; /* new stats */
        struct i40e_hw_port_stats *os = &pf->stats_offset; /* old stats */
+
        /* Get statistics of struct i40e_eth_stats */
        i40e_stat_update_48(hw, I40E_GLPRT_GORCH(hw->port),
                            I40E_GLPRT_GORCL(hw->port),
@@ -1887,6 +1888,12 @@ i40e_read_stats_registers(struct i40e_pf *pf, struct i40e_hw *hw)
                            I40E_GLPRT_BPRCL(hw->port),
                            pf->offset_loaded, &os->eth.rx_broadcast,
                            &ns->eth.rx_broadcast);
+       /* Workaround: CRC size should not be included in byte statistics,
+        * so subtract ETHER_CRC_LEN from the byte counter for each rx packet.
+        */
+       ns->eth.rx_bytes -= (ns->eth.rx_unicast + ns->eth.rx_multicast +
+               ns->eth.rx_broadcast) * ETHER_CRC_LEN;
+
        i40e_stat_update_32(hw, I40E_GLPRT_RDPC(hw->port),
                            pf->offset_loaded, &os->eth.rx_discards,
                            &ns->eth.rx_discards);
@@ -1912,6 +1919,8 @@ i40e_read_stats_registers(struct i40e_pf *pf, struct i40e_hw *hw)
                            I40E_GLPRT_BPTCL(hw->port),
                            pf->offset_loaded, &os->eth.tx_broadcast,
                            &ns->eth.tx_broadcast);
+       ns->eth.tx_bytes -= (ns->eth.tx_unicast + ns->eth.tx_multicast +
+               ns->eth.tx_broadcast) * ETHER_CRC_LEN;
        /* GLPRT_TEPC not supported */
 
        /* additional port specific stats */
@@ -2069,8 +2078,8 @@ i40e_dev_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats)
        stats->opackets = pf->main_vsi->eth_stats.tx_unicast +
                        pf->main_vsi->eth_stats.tx_multicast +
                        pf->main_vsi->eth_stats.tx_broadcast;
-       stats->ibytes   = pf->main_vsi->eth_stats.rx_bytes;
-       stats->obytes   = pf->main_vsi->eth_stats.tx_bytes;
+       stats->ibytes   = ns->eth.rx_bytes;
+       stats->obytes   = ns->eth.tx_bytes;
        stats->oerrors  = ns->eth.tx_errors +
                        pf->main_vsi->eth_stats.tx_errors;
        stats->imcasts  = pf->main_vsi->eth_stats.rx_multicast;