Commit d9b24135 authored by Bruce Allan's avatar Bruce Allan Committed by Jeff Kirsher

e1000e: disable far-end loopback mode on ESB2

The ESB2 LAN includes a debug feature that enables far-end loopback (FELB)
of the SerDes/Kumeran interface.  This feature is activated when receiving
a sequence of symbols that includes a reserved codeword.  On a perfect
link, FELB would never be activated.  In the presence of bit errors, there
is a very small, but non-zero, probability of FELB being activated.

If the FELB is activated, the SerDes link becomes non-functional and must
be reset.  It could also corrupt the switching tables in the switch since
the ESB2 is transmitting packets with a different source MAC address.

This patch disables the FELB feature.
Signed-off-by: default avatarBruce Allan <bruce.w.allan@intel.com>
Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent e357964e
......@@ -836,6 +836,7 @@ static s32 e1000_init_hw_80003es2lan(struct e1000_hw *hw)
struct e1000_mac_info *mac = &hw->mac;
u32 reg_data;
s32 ret_val;
u16 kum_reg_data;
u16 i;
e1000_initialize_hw_bits_80003es2lan(hw);
......@@ -861,6 +862,13 @@ static s32 e1000_init_hw_80003es2lan(struct e1000_hw *hw)
/* Setup link and flow control */
ret_val = e1000e_setup_link(hw);
/* Disable IBIST slave mode (far-end loopback) */
e1000_read_kmrn_reg_80003es2lan(hw, E1000_KMRNCTRLSTA_INBAND_PARAM,
&kum_reg_data);
kum_reg_data |= E1000_KMRNCTRLSTA_IBIST_DISABLE;
e1000_write_kmrn_reg_80003es2lan(hw, E1000_KMRNCTRLSTA_INBAND_PARAM,
kum_reg_data);
/* Set the transmit descriptor write-back policy */
reg_data = er32(TXDCTL(0));
reg_data = (reg_data & ~E1000_TXDCTL_WTHRESH) |
......
......@@ -312,6 +312,7 @@ enum e1e_registers {
#define E1000_KMRNCTRLSTA_DIAG_OFFSET 0x3 /* Kumeran Diagnostic */
#define E1000_KMRNCTRLSTA_TIMEOUTS 0x4 /* Kumeran Timeouts */
#define E1000_KMRNCTRLSTA_INBAND_PARAM 0x9 /* Kumeran InBand Parameters */
#define E1000_KMRNCTRLSTA_IBIST_DISABLE 0x0200 /* Kumeran IBIST Disable */
#define E1000_KMRNCTRLSTA_DIAG_NELPBK 0x1000 /* Nearend Loopback mode */
#define E1000_KMRNCTRLSTA_K1_CONFIG 0x7
#define E1000_KMRNCTRLSTA_K1_ENABLE 0x0002
......
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