Re: [dpdk-dev] [PATCH] net/bnxt: fix PAM4 link negotiation

[Ajit Khaparde <ajit.khaparde@broadcom.com>]

On Sun, Nov 1, 2020 at 6:43 PM Ajit Khaparde <ajit.khaparde@broadcom.com>
wrote:

> In some instances link was not coming up if PAM4 signaling is enabled.
> Added check to disable autoneg if FW indicates auto speeds are zero.
> Use default auto speeds if PAM4 auto speeds is not set.
> Added a fix for forced link setting.
>
> Fixes: c23f9ded0391 ("net/bnxt: support 200G PAM4 link")
>
> Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
>
Applied to dpdk-next-net-brcm. Thanks


> ---
>  drivers/net/bnxt/bnxt_ethdev.c |  4 ++++
>  drivers/net/bnxt/bnxt_hwrm.c   | 22 ++++++++++++++++++++--
>  2 files changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/bnxt/bnxt_ethdev.c
> b/drivers/net/bnxt/bnxt_ethdev.c
> index 21ea370bf5..70edf824bc 100644
> --- a/drivers/net/bnxt/bnxt_ethdev.c
> +++ b/drivers/net/bnxt/bnxt_ethdev.c
> @@ -845,6 +845,10 @@ uint32_t bnxt_get_speed_capabilities(struct bnxt *bp)
>         uint32_t link_speed = bp->link_info->support_speeds;
>         uint32_t speed_capa = 0;
>
> +       /* If PAM4 is configured, use PAM4 supported speed */
> +       if (link_speed == 0 && bp->link_info->support_pam4_speeds > 0)
> +               link_speed = bp->link_info->support_pam4_speeds;
> +
>         if (link_speed & HWRM_PORT_PHY_QCFG_OUTPUT_LINK_SPEED_100MB)
>                 speed_capa |= ETH_LINK_SPEED_100M;
>         if (link_speed & HWRM_PORT_PHY_QCFG_OUTPUT_SUPPORT_SPEEDS_100MBHD)
> diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
> index 84702125cc..24c33185b4 100644
> --- a/drivers/net/bnxt/bnxt_hwrm.c
> +++ b/drivers/net/bnxt/bnxt_hwrm.c
> @@ -1272,9 +1272,10 @@ static int bnxt_hwrm_port_phy_cfg(struct bnxt *bp,
> struct bnxt_link_info *conf)
>
> HWRM_PORT_PHY_CFG_IN_EN_FORCE_PAM4_LINK_SPEED;
>                                 req.force_pam4_link_speed =
>                                         rte_cpu_to_le_16(conf->link_speed);
> -                       }
> -                       req.force_link_speed =
> +                       } else {
> +                               req.force_link_speed =
>                                         rte_cpu_to_le_16(conf->link_speed);
> +                       }
>                 }
>                 /* AutoNeg - Advertise speeds specified. */
>                 if (conf->auto_link_speed_mask &&
> @@ -1370,6 +1371,11 @@ static int bnxt_hwrm_port_phy_qcfg(struct bnxt *bp,
>                     link_info->link_speed, link_info->auto_mode,
>                     link_info->auto_link_speed,
> link_info->auto_link_speed_mask,
>                     link_info->support_speeds,
> link_info->force_link_speed);
> +       PMD_DRV_LOG(DEBUG, "Link
> Signal:%d,PAM::Auto:%x,Support:%x,Force:%x\n",
> +                   link_info->link_signal_mode,
> +                   link_info->auto_pam4_link_speeds,
> +                   link_info->support_pam4_speeds,
> +                   link_info->force_pam4_link_speed);
>         return rc;
>  }
>
> @@ -3071,6 +3077,12 @@ int bnxt_set_hwrm_link_config(struct bnxt *bp, bool
> link_up)
>                 autoneg = 0;
>         }
>
> +       /* No auto speeds and no auto_pam4_link. Disable autoneg */
> +       if (bp->link_info->auto_link_speed == 0 &&
> +           bp->link_info->link_signal_mode &&
> +           bp->link_info->auto_pam4_link_speeds == 0)
> +               autoneg = 0;
> +
>         speed = bnxt_parse_eth_link_speed(dev_conf->link_speeds,
>                                           bp->link_info->link_signal_mode);
>         link_req.phy_flags = HWRM_PORT_PHY_CFG_INPUT_FLAGS_RESET_PHY;
> @@ -3116,6 +3128,12 @@ int bnxt_set_hwrm_link_config(struct bnxt *bp, bool
> link_up)
>                         link_req.link_speed =
> bp->link_info->force_link_speed;
>                 else
>                         link_req.link_speed =
> bp->link_info->auto_link_speed;
> +               /* Auto PAM4 link speed is zero, but auto_link_speed is not
> +                * zero. Use the auto_link_speed.
> +                */
> +               if (bp->link_info->auto_link_speed != 0 &&
> +                   bp->link_info->auto_pam4_link_speeds == 0)
> +                       link_req.link_speed =
> bp->link_info->auto_link_speed;
>         }
>         link_req.duplex =
> bnxt_parse_eth_link_duplex(dev_conf->link_speeds);
>         link_req.auto_pause = bp->link_info->auto_pause;
> --
> 2.21.1 (Apple Git-122.3)
>
>