Commit 36ceeb43 authored by Bruce Allan's avatar Bruce Allan Committed by Jeff Kirsher
Browse files

e1000e: 82579 packet drop workaround

In K1 mode (a MAC/PHY interconnect power mode), the 82579 device shuts down
the Phase Lock Loop (PLL) of the interconnect to save power.  When the PLL
starts working, the 82579 device may start to transfer the packet through
the interconnect before it is fully functional causing packet drops.  This
workaround disables shutting down the PLL in K1 mode for 1G link speed.
Signed-off-by: default avatarBruce Allan <>
Tested-by: default avatarJeff Pieper <>
Signed-off-by: default avatarJeff Kirsher <>
parent 2cb7a9cc
......@@ -135,6 +135,7 @@
/* PHY Power Management Control */
#define HV_PM_CTRL PHY_REG(770, 17)
#define HV_PM_CTRL_PLL_STOP_IN_K1_GIGA 0x100
/* PHY Low Power Idle Control */
#define I82579_LPI_CTRL PHY_REG(772, 20)
......@@ -1708,8 +1709,18 @@ static s32 e1000_k1_workaround_lv(struct e1000_hw *hw)
return ret_val;
if (status_reg & HV_M_STATUS_SPEED_1000) {
u16 pm_phy_reg;
/* LV 1G Packet drop issue wa */
ret_val = e1e_rphy(hw, HV_PM_CTRL, &pm_phy_reg);
if (ret_val)
return ret_val;
pm_phy_reg &= ~HV_PM_CTRL_PLL_STOP_IN_K1_GIGA;
ret_val = e1e_wphy(hw, HV_PM_CTRL, pm_phy_reg);
if (ret_val)
return ret_val;
} else {
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