[PATCH 4.9 45/72] ixgbe: Reduce I2C retry count on X550 devices

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>


[ Upstream commit 3f0d646b720d541309b11e190db58086f446f41e ]

A retry count of 10 is likely to run into problems on X550 devices that
have to detect and reset unresponsive CS4227 devices. So, reduce the I2C
retry count to 3 for X550 and above. This should avoid any possible
regressions in existing devices.

Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Tested-by: Andrew Bowers <andrewx.bowers@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
@@ -113,7 +113,7 @@ static s32 ixgbe_read_i2c_combined_gener
 					       u16 reg, u16 *val, bool lock)
 {
 	u32 swfw_mask = hw->phy.phy_semaphore_mask;
-	int max_retry = 10;
+	int max_retry = 3;
 	int retry = 0;
 	u8 csum_byte;
 	u8 high_bits;
@@ -1764,6 +1764,8 @@ static s32 ixgbe_read_i2c_byte_generic_i
 	u32 swfw_mask = hw->phy.phy_semaphore_mask;
 	bool nack = true;
 
+	if (hw->mac.type >= ixgbe_mac_X550)
+		max_retry = 3;
 	if (ixgbe_is_sfp_probe(hw, byte_offset, dev_addr))
 		max_retry = IXGBE_SFP_DETECT_RETRIES;