[PATCH] ixgbe/base: Manual AN-37 for troublesome link partners for X550 SFI

[Jeff Daly <jeffd@silicom-usa.com>]

Some 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.

Signed-off-by: Jeff Daly <jeffd@silicom-usa.com>
---
 drivers/net/ixgbe/base/ixgbe_type.h |  1 +
 drivers/net/ixgbe/base/ixgbe_x550.c | 51 +++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)

diff --git a/drivers/net/ixgbe/base/ixgbe_type.h b/drivers/net/ixgbe/base/ixgbe_type.h
index b7eec45635..9278b1e64c 100644
--- a/drivers/net/ixgbe/base/ixgbe_type.h
+++ b/drivers/net/ixgbe/base/ixgbe_type.h
@@ -4260,6 +4260,7 @@ struct ixgbe_hw {
 #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		(1u << 20)
diff --git a/drivers/net/ixgbe/base/ixgbe_x550.c b/drivers/net/ixgbe/base/ixgbe_x550.c
index 8810d1658e..649d834715 100644
--- a/drivers/net/ixgbe/base/ixgbe_x550.c
+++ b/drivers/net/ixgbe/base/ixgbe_x550.c
@@ -2676,6 +2676,57 @@ 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);
+	status |= 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);
+				
+	/* 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);
+	status |= 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);
+	status |= 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);
+	status |= 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);
+	status |= 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);
 
-- 
2.25.1