Revert "e1000e: Separate signaling for link check/link up"

This reverts commit 0816c8e2c8c5f4b1da0acdbd9a7598e0c24fad73.
This reverts commit 2295213c48da36c48866424a180a933a6789047e.
This reverts commit d3604515c9eda464a92e8e67aae82dfe07fe3c98.

Commit 0816c8e2c8c5 ("e1000e: Separate signaling for link check/link up")
changed what happens to the link status when there is an error which
happens after "get_link_status = false" in the copper check_for_link
callbacks. Previously, such an error would be ignored and the link
considered up. After that commit, any error implies that the link is down.

Revert commit 0816c8e2c8c5 ("e1000e: Separate signaling for link check/link
up") and its followups. After reverting, the race condition described in
the log of commit 0816c8e2c8c5 is reintroduced. It may still be triggered
by LSC events but this should keep the link down in case the link is
electrically unstable, as discussed. The race may no longer be
triggered by RXO events because commit 7787cd116c75 ("e1000e: Avoid
receiver overrun interrupt bursts") restored reading icr in the Other
handler.

Link: https://lkml.org/lkml/2018/3/1/789
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index ff308b05d68cc91efa7b195db9952d368553557f..d6d4ed7acf03117232778a82a757ee44d65f765a 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -1367,9 +1367,6 @@ out:
  *  Checks to see of the link status of the hardware has changed.  If a
  *  change in link status has been detected, then we read the PHY registers
  *  to get the current speed/duplex if link exists.
- *
- *  Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
- *  up).
  **/
 static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 {
@@ -1385,7 +1382,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
         * Change or Rx Sequence Error interrupt.
         */
        if (!mac->get_link_status)
-               return 1;
+               return 0;
 
        /* First we want to see if the MII Status Register reports
         * link.  If so, then we want to get the current speed/duplex
@@ -1602,7 +1599,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
         * we have already determined whether we have link or not.
         */
        if (!mac->autoneg)
-               return 1;
+               return -E1000_ERR_CONFIG;
 
        /* Auto-Neg is enabled.  Auto Speed Detection takes care
         * of MAC speed/duplex configuration.  So we only need to
@@ -1616,12 +1613,10 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
         * different link partner.
         */
        ret_val = e1000e_config_fc_after_link_up(hw);
-       if (ret_val) {
+       if (ret_val)
                e_dbg("Error configuring flow control\n");
-               return ret_val;
-       }
 
-       return 1;
+       return ret_val;
 }
 
 static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)

diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
index db735644b31214e8c35216d35642531c713abbb1..b322011ec2828a704fcac2acf9b949f8c955df48 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/mac.c
+++ b/drivers/net/ethernet/intel/e1000e/mac.c
@@ -410,9 +410,6 @@ void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)
  *  Checks to see of the link status of the hardware has changed.  If a
  *  change in link status has been detected, then we read the PHY registers
  *  to get the current speed/duplex if link exists.
- *
- *  Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
- *  up).
  **/
 s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
 {
@@ -426,7 +423,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
         * Change or Rx Sequence Error interrupt.
         */
        if (!mac->get_link_status)
-               return 1;
+               return 0;
 
        /* First we want to see if the MII Status Register reports
         * link.  If so, then we want to get the current speed/duplex
@@ -450,7 +447,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
         * we have already determined whether we have link or not.
         */
        if (!mac->autoneg)
-               return 1;
+               return -E1000_ERR_CONFIG;
 
        /* Auto-Neg is enabled.  Auto Speed Detection takes care
         * of MAC speed/duplex configuration.  So we only need to
@@ -464,12 +461,10 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
         * different link partner.
         */
        ret_val = e1000e_config_fc_after_link_up(hw);
-       if (ret_val) {
+       if (ret_val)
                e_dbg("Error configuring flow control\n");
-               return ret_val;
-       }
 
-       return 1;
+       return ret_val;
 }
 
 /**

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index c0f23446bf26b0fed3b2c7f59c919b43d03a0411..dc853b0863aff1b4f66043a1fe70bca6112d5aeb 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5090,7 +5090,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter)
        case e1000_media_type_copper:
                if (hw->mac.get_link_status) {
                        ret_val = hw->mac.ops.check_for_link(hw);
-                       link_active = ret_val > 0;
+                       link_active = !hw->mac.get_link_status;
                } else {
                        link_active = true;
                }