[PATCH v6 06/15] net/txgbe: set i2c sda hold time

[Zaiyu Wang <zaiyuwang@trustnetic.com>]

The data_in_hold_time measured on the oscilloscope does not meet the
hardware requirement, which can corrupt SFP EEPROM reads over I2C.

Set the I2C SDA hold time to 100 (0x64) I2C clock periods for both
RX and TX in txgbe_i2c_start().

Fixes: 00970f6398c8 ("net/txgbe: fix reading SFP module SFF-8472 data")
Cc: stable@dpdk.org

Signed-off-by: Zaiyu Wang <zaiyuwang@trustnetic.com>
---
 drivers/net/txgbe/base/txgbe_phy.c  | 3 +++
 drivers/net/txgbe/base/txgbe_regs.h | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/drivers/net/txgbe/base/txgbe_phy.c b/drivers/net/txgbe/base/txgbe_phy.c
index 2fbe50e242..8b653f0aeb 100644
--- a/drivers/net/txgbe/base/txgbe_phy.c
+++ b/drivers/net/txgbe/base/txgbe_phy.c
@@ -1334,6 +1334,9 @@ static void txgbe_i2c_start(struct txgbe_hw *hw, u8 dev_addr)
 	wr32(hw, TXGBE_I2CSCLTMOUT, 0xFFFFFF);
 	wr32(hw, TXGBE_I2CSDATMOUT, 0xFFFFFF);
 
+	wr32m(hw, TXGBE_I2C_SDA_HOLD,
+		TXGBE_I2C_SDA_RX_HOLD | TXGBE_I2C_SDA_TX_HOLD, 0x640064);
+
 	wr32(hw, TXGBE_I2CICM, 0);
 	wr32(hw, TXGBE_I2CENA, 1);
 }
diff --git a/drivers/net/txgbe/base/txgbe_regs.h b/drivers/net/txgbe/base/txgbe_regs.h
index bf46a80862..b0042dc0d6 100644
--- a/drivers/net/txgbe/base/txgbe_regs.h
+++ b/drivers/net/txgbe/base/txgbe_regs.h
@@ -1610,6 +1610,9 @@ enum txgbe_5tuple_protocol {
 #define   TXGBE_I2CSTAT_MST          ((1U << 5))
 #define TXGBE_I2CSCLTMOUT            0x0149AC
 #define TXGBE_I2CSDATMOUT            0x0149B0 /*I2C SDA Stuck at Low Timeout*/
+#define TXGBE_I2C_SDA_HOLD              0x1497C /* SDA hold time length reg */
+#define TXGBE_I2C_SDA_RX_HOLD           0xff0000 /* SDA rx hold time length reg */
+#define TXGBE_I2C_SDA_TX_HOLD           0xffff /* SDA tx hold time length reg */
 
 /* port cfg Registers */
 #define TXGBE_PORTSTAT                  0x014404
-- 
2.55.0.windows.2