From daf56e406a94675d454f996cab56c3d0b0a0d8a6 Mon Sep 17 00:00:00 2001
From: Carolyn Wyborny <carolyn.wyborny@intel.com>
Date: Tue, 23 Oct 2012 12:54:33 +0000
Subject: igb: Fix SerDes autoneg flow control.
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>
---
drivers/net/ethernet/intel/igb/e1000_mac.c | 124 +++++++++++++++++++++++++++++
1 file changed, 124 insertions(+)
(limited to 'drivers/net/ethernet/intel/igb/e1000_mac.c')
diff --git a/drivers/net/ethernet/intel/igb/e1000_mac.c b/drivers/net/ethernet/intel/igb/e1000_mac.c
index 7acddfe9e6d5..101e6e4da97f 100644
--- a/drivers/net/ethernet/intel/igb/e1000_mac.c
+++ b/drivers/net/ethernet/intel/igb/e1000_mac.c
@@ -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;
@@ -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;
--
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