Commit 651fb102 authored by Bruce Allan's avatar Bruce Allan Committed by Jeff Kirsher
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e1000e: 82577: workaround for link drop issue

When connected to certain switches, the 82577 PHY might drop link
unexpectedly.  Work around the issue by setting the Mean Square Error
higher than the hardware default.

Signed-off-by: default avatarBruce Allan <>
Tested-by: default avatarAaron Brown <>
Signed-off-by: default avatarJeff Kirsher <>
parent 4ddc48a9
......@@ -157,7 +157,8 @@
#define I82579_EMI_ADDR 0x10
#define I82579_EMI_DATA 0x11
#define I82579_LPI_UPDATE_TIMER 0x4805 /* in 40ns units + 40 ns base value */
#define I82579_MSE_THRESHOLD 0x084F /* Mean Square Error Threshold */
#define I82579_MSE_THRESHOLD 0x084F /* 82579 Mean Square Error Threshold */
#define I82577_MSE_THRESHOLD 0x0887 /* 82577 Mean Square Error Threshold */
#define I82579_MSE_LINK_DOWN 0x2411 /* MSE count before dropping link */
#define I217_EEE_ADVERTISEMENT 0x8001 /* IEEE MMD Register 7.60 */
#define I217_EEE_LP_ABILITY 0x8002 /* IEEE MMD Register 7.61 */
......@@ -1809,6 +1810,11 @@ static s32 e1000_hv_phy_workarounds_ich8lan(struct e1000_hw *hw)
if (ret_val)
goto release;
ret_val = e1e_wphy_locked(hw, BM_PORT_GEN_CFG, phy_data & 0x00FF);
if (ret_val)
goto release;
/* set MSE higher to enable link to stay up when noise is high */
ret_val = e1000_write_emi_reg_locked(hw, I82577_MSE_THRESHOLD, 0x0034);
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