[38/38] e1000e: workaround for packet drop on 82579 at 100Mbps

Greg KH
2011-10-11T17:07:54Z

From: Bruce Allan <bruce.w.allan@intel.com>

commit 0ed013e28fe853244f4972cf18d8e2bd62eeb8fc upstream.

The MAC can drop short packets when the PHY detects noise on the line at
100Mbps due to a timing issue. Workaround the issue by increasing the PLL
counter so the PHY properly recognizes the synchronization pattern from the
MAC.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Leann Ogasawara <leann.ogasawara@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/e1000e/ich8lan.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)

--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -137,8 +137,9 @@
#define HV_PM_CTRL PHY_REG(770, 17)

/* PHY Low Power Idle Control */
-#define I82579_LPI_CTRL PHY_REG(772, 20)
-#define I82579_LPI_CTRL_ENABLE_MASK 0x6000
+#define I82579_LPI_CTRL PHY_REG(772, 20)
+#define I82579_LPI_CTRL_ENABLE_MASK 0x6000
+#define I82579_LPI_CTRL_FORCE_PLL_LOCK_COUNT 0x80

/* EMI Registers */
#define I82579_EMI_ADDR 0x10
@@ -1611,6 +1612,7 @@ static s32 e1000_k1_workaround_lv(struct
s32 ret_val = 0;
u16 status_reg = 0;
u32 mac_reg;
+ u16 phy_reg;

if (hw->mac.type != e1000_pch2lan)
goto out;
@@ -1625,12 +1627,19 @@ static s32 e1000_k1_workaround_lv(struct
mac_reg = er32(FEXTNVM4);
mac_reg &= ~E1000_FEXTNVM4_BEACON_DURATION_MASK;

- if (status_reg & HV_M_STATUS_SPEED_1000)
+ ret_val = e1e_rphy(hw, I82579_LPI_CTRL, &phy_reg);
+ if (ret_val)
+ goto out;
+
+ if (status_reg & HV_M_STATUS_SPEED_1000) {
mac_reg |= E1000_FEXTNVM4_BEACON_DURATION_8USEC;
- else
+ phy_reg &= ~I82579_LPI_CTRL_FORCE_PLL_LOCK_COUNT;
+ } else {
mac_reg |= E1000_FEXTNVM4_BEACON_DURATION_16USEC;
-
+ phy_reg |= I82579_LPI_CTRL_FORCE_PLL_LOCK_COUNT;
+ }
ew32(FEXTNVM4, mac_reg);
+ ret_val = e1e_wphy(hw, I82579_LPI_CTRL, phy_reg);
}