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igb: Fix SerDes autoneg flow control.
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This patch enables flow control to be set in SerDes autoneg mode.  This is
done the way it is done for copper, but relies on a different set of register/bit
checks since this is all done within the MAC registers.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
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Carolyn Wyborny authored and Jeff Kirsher committed Dec 1, 2012
1 parent 3860a0b commit daf56e4
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Showing 3 changed files with 166 additions and 8 deletions.
43 changes: 35 additions & 8 deletions drivers/net/ethernet/intel/igb/e1000_82575.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1028,6 +1028,15 @@ static s32 igb_check_for_link_82575(struct e1000_hw *hw)
* continue to check for link.
*/
hw->mac.get_link_status = !hw->mac.serdes_has_link;

/* Configure Flow Control now that Auto-Neg has completed.
* First, we need to restore the desired flow control
* settings because we may have had to re-autoneg with a
* different link partner.
*/
ret_val = igb_config_fc_after_link_up(hw);
if (ret_val)
hw_dbg("Error configuring flow control\n");
} else {
ret_val = igb_check_for_copper_link(hw);
}
Expand Down Expand Up @@ -1345,7 +1354,7 @@ static s32 igb_setup_copper_link_82575(struct e1000_hw *hw)
**/
static s32 igb_setup_serdes_link_82575(struct e1000_hw *hw)
{
u32 ctrl_ext, ctrl_reg, reg;
u32 ctrl_ext, ctrl_reg, reg, anadv_reg;
bool pcs_autoneg;
s32 ret_val = E1000_SUCCESS;
u16 data;
Expand Down Expand Up @@ -1433,27 +1442,45 @@ static s32 igb_setup_serdes_link_82575(struct e1000_hw *hw)
reg &= ~(E1000_PCS_LCTL_AN_ENABLE | E1000_PCS_LCTL_FLV_LINK_UP |
E1000_PCS_LCTL_FSD | E1000_PCS_LCTL_FORCE_LINK);

/*
* We force flow control to prevent the CTRL register values from being
* overwritten by the autonegotiated flow control values
*/
reg |= E1000_PCS_LCTL_FORCE_FCTRL;

if (pcs_autoneg) {
/* Set PCS register for autoneg */
reg |= E1000_PCS_LCTL_AN_ENABLE | /* Enable Autoneg */
E1000_PCS_LCTL_AN_RESTART; /* Restart autoneg */

/* Disable force flow control for autoneg */
reg &= ~E1000_PCS_LCTL_FORCE_FCTRL;

/* Configure flow control advertisement for autoneg */
anadv_reg = rd32(E1000_PCS_ANADV);
anadv_reg &= ~(E1000_TXCW_ASM_DIR | E1000_TXCW_PAUSE);
switch (hw->fc.requested_mode) {
case e1000_fc_full:
case e1000_fc_rx_pause:
anadv_reg |= E1000_TXCW_ASM_DIR;
anadv_reg |= E1000_TXCW_PAUSE;
break;
case e1000_fc_tx_pause:
anadv_reg |= E1000_TXCW_ASM_DIR;
break;
default:
break;
}
wr32(E1000_PCS_ANADV, anadv_reg);

hw_dbg("Configuring Autoneg:PCS_LCTL=0x%08X\n", reg);
} else {
/* Set PCS register for forced link */
reg |= E1000_PCS_LCTL_FSD; /* Force Speed */

/* Force flow control for forced link */
reg |= E1000_PCS_LCTL_FORCE_FCTRL;

hw_dbg("Configuring Forced Link:PCS_LCTL=0x%08X\n", reg);
}

wr32(E1000_PCS_LCTL, reg);

if (!igb_sgmii_active_82575(hw))
if (!pcs_autoneg && !igb_sgmii_active_82575(hw))
igb_force_mac_fc(hw);

return ret_val;
Expand Down
7 changes: 7 additions & 0 deletions drivers/net/ethernet/intel/igb/e1000_defines.h
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Original file line number Diff line number Diff line change
Expand Up @@ -431,6 +431,10 @@
#define FLOW_CONTROL_ADDRESS_HIGH 0x00000100
#define FLOW_CONTROL_TYPE 0x8808

/* Transmit Config Word */
#define E1000_TXCW_ASM_DIR 0x00000100 /* TXCW astm pause direction */
#define E1000_TXCW_PAUSE 0x00000080 /* TXCW sym pause request */

/* 802.1q VLAN Packet Size */
#define VLAN_TAG_SIZE 4 /* 802.3ac tag (not DMA'd) */
#define E1000_VLAN_FILTER_TBL_SIZE 128 /* VLAN Filter Table (4096 bits) */
Expand Down Expand Up @@ -539,6 +543,9 @@
/* mPHY Near End Digital Loopback Override Bit */
#define E1000_MPHY_PCS_CLK_REG_DIGINELBEN 0x10

#define E1000_PCS_LCTL_FORCE_FCTRL 0x80
#define E1000_PCS_LSTS_AN_COMPLETE 0x10000

/* PHY Control Register */
#define MII_CR_FULL_DUPLEX 0x0100 /* FDX =1, half duplex =0 */
#define MII_CR_RESTART_AUTO_NEG 0x0200 /* Restart auto negotiation */
Expand Down
124 changes: 124 additions & 0 deletions drivers/net/ethernet/intel/igb/e1000_mac.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -839,6 +839,7 @@ s32 igb_config_fc_after_link_up(struct e1000_hw *hw)
{
struct e1000_mac_info *mac = &hw->mac;
s32 ret_val = 0;
u32 pcs_status_reg, pcs_adv_reg, pcs_lp_ability_reg, pcs_ctrl_reg;
u16 mii_status_reg, mii_nway_adv_reg, mii_nway_lp_ability_reg;
u16 speed, duplex;

Expand Down Expand Up @@ -1040,6 +1041,129 @@ s32 igb_config_fc_after_link_up(struct e1000_hw *hw)
goto out;
}
}
/* Check for the case where we have SerDes media and auto-neg is
* enabled. In this case, we need to check and see if Auto-Neg
* has completed, and if so, how the PHY and link partner has
* flow control configured.
*/
if ((hw->phy.media_type == e1000_media_type_internal_serdes)
&& mac->autoneg) {
/* Read the PCS_LSTS and check to see if AutoNeg
* has completed.
*/
pcs_status_reg = rd32(E1000_PCS_LSTAT);

if (!(pcs_status_reg & E1000_PCS_LSTS_AN_COMPLETE)) {
hw_dbg("PCS Auto Neg has not completed.\n");
return ret_val;
}

/* The AutoNeg process has completed, so we now need to
* read both the Auto Negotiation Advertisement
* Register (PCS_ANADV) and the Auto_Negotiation Base
* Page Ability Register (PCS_LPAB) to determine how
* flow control was negotiated.
*/
pcs_adv_reg = rd32(E1000_PCS_ANADV);
pcs_lp_ability_reg = rd32(E1000_PCS_LPAB);

/* Two bits in the Auto Negotiation Advertisement Register
* (PCS_ANADV) and two bits in the Auto Negotiation Base
* Page Ability Register (PCS_LPAB) determine flow control
* for both the PHY and the link partner. The following
* table, taken out of the IEEE 802.3ab/D6.0 dated March 25,
* 1999, describes these PAUSE resolution bits and how flow
* control is determined based upon these settings.
* NOTE: DC = Don't Care
*
* LOCAL DEVICE | LINK PARTNER
* PAUSE | ASM_DIR | PAUSE | ASM_DIR | NIC Resolution
*-------|---------|-------|---------|--------------------
* 0 | 0 | DC | DC | e1000_fc_none
* 0 | 1 | 0 | DC | e1000_fc_none
* 0 | 1 | 1 | 0 | e1000_fc_none
* 0 | 1 | 1 | 1 | e1000_fc_tx_pause
* 1 | 0 | 0 | DC | e1000_fc_none
* 1 | DC | 1 | DC | e1000_fc_full
* 1 | 1 | 0 | 0 | e1000_fc_none
* 1 | 1 | 0 | 1 | e1000_fc_rx_pause
*
* Are both PAUSE bits set to 1? If so, this implies
* Symmetric Flow Control is enabled at both ends. The
* ASM_DIR bits are irrelevant per the spec.
*
* For Symmetric Flow Control:
*
* LOCAL DEVICE | LINK PARTNER
* PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
*-------|---------|-------|---------|--------------------
* 1 | DC | 1 | DC | e1000_fc_full
*
*/
if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
(pcs_lp_ability_reg & E1000_TXCW_PAUSE)) {
/* Now we need to check if the user selected Rx ONLY
* of pause frames. In this case, we had to advertise
* FULL flow control because we could not advertise Rx
* ONLY. Hence, we must now check to see if we need to
* turn OFF the TRANSMISSION of PAUSE frames.
*/
if (hw->fc.requested_mode == e1000_fc_full) {
hw->fc.current_mode = e1000_fc_full;
hw_dbg("Flow Control = FULL.\n");
} else {
hw->fc.current_mode = e1000_fc_rx_pause;
hw_dbg("Flow Control = Rx PAUSE frames only.\n");
}
}
/* For receiving PAUSE frames ONLY.
*
* LOCAL DEVICE | LINK PARTNER
* PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
*-------|---------|-------|---------|--------------------
* 0 | 1 | 1 | 1 | e1000_fc_tx_pause
*/
else if (!(pcs_adv_reg & E1000_TXCW_PAUSE) &&
(pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
(pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
(pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
hw->fc.current_mode = e1000_fc_tx_pause;
hw_dbg("Flow Control = Tx PAUSE frames only.\n");
}
/* For transmitting PAUSE frames ONLY.
*
* LOCAL DEVICE | LINK PARTNER
* PAUSE | ASM_DIR | PAUSE | ASM_DIR | Result
*-------|---------|-------|---------|--------------------
* 1 | 1 | 0 | 1 | e1000_fc_rx_pause
*/
else if ((pcs_adv_reg & E1000_TXCW_PAUSE) &&
(pcs_adv_reg & E1000_TXCW_ASM_DIR) &&
!(pcs_lp_ability_reg & E1000_TXCW_PAUSE) &&
(pcs_lp_ability_reg & E1000_TXCW_ASM_DIR)) {
hw->fc.current_mode = e1000_fc_rx_pause;
hw_dbg("Flow Control = Rx PAUSE frames only.\n");
} else {
/* Per the IEEE spec, at this point flow control
* should be disabled.
*/
hw->fc.current_mode = e1000_fc_none;
hw_dbg("Flow Control = NONE.\n");
}

/* Now we call a subroutine to actually force the MAC
* controller to use the correct flow control settings.
*/
pcs_ctrl_reg = rd32(E1000_PCS_LCTL);
pcs_ctrl_reg |= E1000_PCS_LCTL_FORCE_FCTRL;
wr32(E1000_PCS_LCTL, pcs_ctrl_reg);

ret_val = igb_force_mac_fc(hw);
if (ret_val) {
hw_dbg("Error forcing flow control settings\n");
return ret_val;
}
}

out:
return ret_val;
Expand Down

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