[Intel-wired-lan] [PATCH] ixgbe: Manual AN-37 for troublesome link partners for X550 SFI

[Tony Nguyen <anthony.l.nguyen@intel.com>]

On 3/16/2022 12:27 PM, Jeff Daly wrote:
> Some (Juniper MX5) SFP link partners exhibit a disinclination to
> autonegotiate with X550 configured in SFI mode.  This patch enables
> a manual AN-37 restart to work around the problem.

Hi Jeff,

I talked to the ixgbe team about this and we need a bit more time to 
look this over. Will keep you updated.

> Signed-off-by: Jeff Daly <jeffd@silicom-usa.com>
> ---
>   drivers/net/ethernet/intel/ixgbe/ixgbe_type.h |  3 ++
>   drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c | 50 +++++++++++++++++++
>   2 files changed, 53 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
> index 2647937f7f4d..dc8a259fda5f 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
> @@ -3705,7 +3705,9 @@ struct ixgbe_info {
>   #define IXGBE_KRM_LINK_S1(P)		((P) ? 0x8200 : 0x4200)
>   #define IXGBE_KRM_LINK_CTRL_1(P)	((P) ? 0x820C : 0x420C)
>   #define IXGBE_KRM_AN_CNTL_1(P)		((P) ? 0x822C : 0x422C)
> +#define IXGBE_KRM_AN_CNTL_4(P)		((P) ? 0x8238 : 0x4238)
>   #define IXGBE_KRM_AN_CNTL_8(P)		((P) ? 0x8248 : 0x4248)
> +#define IXGBE_KRM_PCS_KX_AN(P)		((P) ? 0x9918 : 0x5918)
>   #define IXGBE_KRM_SGMII_CTRL(P)		((P) ? 0x82A0 : 0x42A0)
>   #define IXGBE_KRM_LP_BASE_PAGE_HIGH(P)	((P) ? 0x836C : 0x436C)
>   #define IXGBE_KRM_DSP_TXFFE_STATE_4(P)	((P) ? 0x8634 : 0x4634)
> @@ -3715,6 +3717,7 @@ struct ixgbe_info {
>   #define IXGBE_KRM_PMD_FLX_MASK_ST20(P)	((P) ? 0x9054 : 0x5054)
>   #define IXGBE_KRM_TX_COEFF_CTRL_1(P)	((P) ? 0x9520 : 0x5520)
>   #define IXGBE_KRM_RX_ANA_CTL(P)		((P) ? 0x9A00 : 0x5A00)
> +#define IXGBE_KRM_FLX_TMRS_CTRL_ST31(P)	((P) ? 0x9180 : 0x5180)
>   
>   #define IXGBE_KRM_PMD_FLX_MASK_ST20_SFI_10G_DA		~(0x3 << 20)
>   #define IXGBE_KRM_PMD_FLX_MASK_ST20_SFI_10G_SR		BIT(20)
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
> index e4b50c7781ff..f48a422ae83f 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c
> @@ -1725,6 +1725,56 @@ static s32 ixgbe_setup_sfi_x550a(struct ixgbe_hw *hw, ixgbe_link_speed *speed)
>   				IXGBE_KRM_PMD_FLX_MASK_ST20(hw->bus.lan_id),
>   				IXGBE_SB_IOSF_TARGET_KR_PHY, reg_val);
>   
> +	/* change mode enforcement rules to hybrid */
> +	status = mac->ops.read_iosf_sb_reg(hw,
> +				IXGBE_KRM_FLX_TMRS_CTRL_ST31(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, &reg_val);
> +	reg_val |= 0x0400;
> +
> +	status = mac->ops.write_iosf_sb_reg(hw,
> +				IXGBE_KRM_FLX_TMRS_CTRL_ST31(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, reg_val);

I don't see a need for all the status assignments, they're not being 
used before being overwritten.

Thanks,

Tony

> +	/* manually control the config */
> +	status = mac->ops.read_iosf_sb_reg(hw,
> +				IXGBE_KRM_LINK_CTRL_1(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, &reg_val);
> +	reg_val |= 0x20002240;
> +
> +	status = mac->ops.write_iosf_sb_reg(hw,
> +				IXGBE_KRM_LINK_CTRL_1(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, reg_val);
> +
> +	/* move the AN base page values */
> +	status = mac->ops.read_iosf_sb_reg(hw,
> +				IXGBE_KRM_PCS_KX_AN(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, &reg_val);
> +	reg_val |= 0x1;
> +
> +	status = mac->ops.write_iosf_sb_reg(hw,
> +				IXGBE_KRM_PCS_KX_AN(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, reg_val);
> +
> +	/* set the AN37 over CB mode */
> +	status = mac->ops.read_iosf_sb_reg(hw,
> +				IXGBE_KRM_AN_CNTL_4(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, &reg_val);
> +	reg_val |= 0x20000000;
> +
> +	status = mac->ops.write_iosf_sb_reg(hw,
> +				IXGBE_KRM_AN_CNTL_4(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, reg_val);
> +
> +	/* restart AN manually */
> +	status = mac->ops.read_iosf_sb_reg(hw,
> +				IXGBE_KRM_LINK_CTRL_1(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, &reg_val);
> +	reg_val |= IXGBE_KRM_LINK_CTRL_1_TETH_AN_RESTART;
> +
> +	status = mac->ops.write_iosf_sb_reg(hw,
> +				IXGBE_KRM_LINK_CTRL_1(hw->bus.lan_id),
> +				IXGBE_SB_IOSF_TARGET_KR_PHY, reg_val);
> +
>   	/* Toggle port SW reset by AN reset. */
>   	status = ixgbe_restart_an_internal_phy_x550em(hw);
>