[Skiboot] [RFC 03/12] npu2-hw-procedures: Fix link retraining on reset

[Frederic Barrat]

Link retraining was showing reliability problems due to some
opencapi-only settings not being optimized. This patch updates some
extra PHY state, as agreed with the PHY team. Though they mostly
impact link retraining behavior, they should also be set at boot.

Signed-off-by: Frederic Barrat <fbarrat at linux.ibm.com>
---
 hw/npu2-hw-procedures.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/hw/npu2-hw-procedures.c b/hw/npu2-hw-procedures.c
index 548dae16..98e93191 100644
--- a/hw/npu2-hw-procedures.c
+++ b/hw/npu2-hw-procedures.c
@@ -68,8 +68,14 @@ static struct npu2_phy_reg NPU2_PHY_RX_PR_FW_OFF	   = {0x08a, 56, 1};
 static struct npu2_phy_reg NPU2_PHY_RX_PR_FW_INERTIA_AMT   = {0x08a, 57, 3};
 static struct npu2_phy_reg NPU2_PHY_RX_CFG_LTE_MC	   = {0x000, 60, 4};
 static struct npu2_phy_reg NPU2_PHY_RX_A_INTEG_COARSE_GAIN = {0x00a, 48, 4};
+static struct npu2_phy_reg NPU2_PHY_RX_A_CTLE_COARSE	   = {0x00c, 48, 5};
+static struct npu2_phy_reg NPU2_PHY_RX_A_CTLE_GAIN	   = {0x00c, 53, 4};
 static struct npu2_phy_reg NPU2_PHY_RX_B_INTEG_COARSE_GAIN = {0x026, 48, 4};
+static struct npu2_phy_reg NPU2_PHY_RX_B_CTLE_COARSE	   = {0x028, 48, 5};
+static struct npu2_phy_reg NPU2_PHY_RX_B_CTLE_GAIN	   = {0x028, 53, 4};
 static struct npu2_phy_reg NPU2_PHY_RX_E_INTEG_COARSE_GAIN = {0x030, 48, 4};
+static struct npu2_phy_reg NPU2_PHY_RX_E_CTLE_COARSE	   = {0x032, 48, 5};
+static struct npu2_phy_reg NPU2_PHY_RX_E_CTLE_GAIN	   = {0x032, 53, 4};
 
 /* These registers are per-PHY, not per lane */
 static struct npu2_phy_reg NPU2_PHY_RX_SPEED_SELECT	       = {0x262, 51, 2};
@@ -437,6 +443,16 @@ static uint32_t phy_reset_complete(struct npu2_dev *ndev)
 		phy_write_lane(ndev, &NPU2_PHY_RX_A_INTEG_COARSE_GAIN, lane, 11);
 		phy_write_lane(ndev, &NPU2_PHY_RX_B_INTEG_COARSE_GAIN, lane, 11);
 		phy_write_lane(ndev, &NPU2_PHY_RX_E_INTEG_COARSE_GAIN, lane, 11);
+
+		if (ndev->type == NPU2_DEV_TYPE_OPENCAPI) {
+			phy_write_lane(ndev, &NPU2_PHY_RX_A_CTLE_GAIN, lane, 0);
+			phy_write_lane(ndev, &NPU2_PHY_RX_B_CTLE_GAIN, lane, 0);
+			phy_write_lane(ndev, &NPU2_PHY_RX_E_CTLE_GAIN, lane, 0);
+
+			phy_write_lane(ndev, &NPU2_PHY_RX_A_CTLE_COARSE, lane, 20);
+			phy_write_lane(ndev, &NPU2_PHY_RX_B_CTLE_COARSE, lane, 20);
+			phy_write_lane(ndev, &NPU2_PHY_RX_E_CTLE_COARSE, lane, 20);
+		}
 	}
 
 	set_iovalid(ndev, true);
-- 
2.21.0