e1000e: disable far-end loopback mode on ESB2 (d9b24135) · Commits · 戴 / test

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:

Bruce Allan <bruce.w.allan@intel.com> Tested-by:

Aaron Brown <aaron.f.brown@intel.com> Signed-off-by:

Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/e1000e/es2lan.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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) \|

drivers/net/e1000e/hw.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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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