net/mlx5: fix inconsistent link status query

ETHTOOL_GLINKSETTINGS ioctl call in mlx5 pmd returns inconsistent
link status due to which any application relying on it would not
function correctly.

Fixes: 188408719888 ("net/mlx5: fix support for newer link speeds")
Cc: stable@dpdk.org
Signed-off-by: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index b70b7b9..1644546 100644 (file)
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -119,6 +119,7 @@ struct ethtool_link_settings {
 #define ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT 38
 #define ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT 39
 #endif
+#define ETHTOOL_LINK_MODE_MASK_MAX_KERNEL_NU32 (SCHAR_MAX)
 
 /**
  * Return private structure associated with an Ethernet device.
@@ -807,9 +808,12 @@ static int
 mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete)
 {
        struct priv *priv = mlx5_get_priv(dev);
-       struct ethtool_link_settings edata = {
-               .cmd = ETHTOOL_GLINKSETTINGS,
-       };
+       __extension__ struct {
+               struct ethtool_link_settings edata;
+               uint32_t link_mode_data[3 *
+                                       ETHTOOL_LINK_MODE_MASK_MAX_KERNEL_NU32];
+       } ecmd;
+
        struct ifreq ifr;
        struct rte_eth_link dev_link;
        uint64_t sc;
@@ -822,15 +826,23 @@ mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete)
        memset(&dev_link, 0, sizeof(dev_link));
        dev_link.link_status = ((ifr.ifr_flags & IFF_UP) &&
                                (ifr.ifr_flags & IFF_RUNNING));
-       ifr.ifr_data = (void *)&edata;
+       memset(&ecmd, 0, sizeof(ecmd));
+       ecmd.edata.cmd = ETHTOOL_GLINKSETTINGS;
+       ifr.ifr_data = (void *)&ecmd;
        if (priv_ifreq(priv, SIOCETHTOOL, &ifr)) {
                DEBUG("ioctl(SIOCETHTOOL, ETHTOOL_GLINKSETTINGS) failed: %s",
                      strerror(errno));
                return -1;
        }
-       dev_link.link_speed = edata.speed;
-       sc = edata.link_mode_masks[0] |
-               ((uint64_t)edata.link_mode_masks[1] << 32);
+       ecmd.edata.link_mode_masks_nwords = -ecmd.edata.link_mode_masks_nwords;
+       if (priv_ifreq(priv, SIOCETHTOOL, &ifr)) {
+               DEBUG("ioctl(SIOCETHTOOL, ETHTOOL_GLINKSETTINGS) failed: %s",
+                     strerror(errno));
+               return -1;
+       }
+       dev_link.link_speed = ecmd.edata.speed;
+       sc = ecmd.edata.link_mode_masks[0] |
+               ((uint64_t)ecmd.edata.link_mode_masks[1] << 32);
        priv->link_speed_capa = 0;
        if (sc & ETHTOOL_LINK_MODE_Autoneg_BIT)
                priv->link_speed_capa |= ETH_LINK_SPEED_AUTONEG;
@@ -866,7 +878,7 @@ mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete)
                  ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT |
                  ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT))
                priv->link_speed_capa |= ETH_LINK_SPEED_100G;
-       dev_link.link_duplex = ((edata.duplex == DUPLEX_HALF) ?
+       dev_link.link_duplex = ((ecmd.edata.duplex == DUPLEX_HALF) ?
                                ETH_LINK_HALF_DUPLEX : ETH_LINK_FULL_DUPLEX);
        dev_link.link_autoneg = !(dev->data->dev_conf.link_speeds &
                                  ETH_LINK_SPEED_FIXED);