Revert "e1000e: fix cyclic resets at link up with active tx"

This reverts commit 0f9e980bf5ee1a97e2e401c846b2af989eb21c61.

That change cased false-positive warning about hardware hang:

e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
e1000e 0000:00:1f.6 eth0: Detected Hardware Unit Hang:
   TDH                  <0>
   TDT                  <1>
   next_to_use          <1>
   next_to_clean        <0>
buffer_info[next_to_clean]:
   time_stamp           <fffba7a7>
   next_to_watch        <0>
   jiffies              <fffbb140>
   next_to_watch.status <0>
MAC Status             <40080080>
PHY Status             <7949>
PHY 1000BASE-T Status  <0>
PHY Extended Status    <3000>
PCI Status             <10>
e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx

Besides warning everything works fine.
Original issue will be fixed property in following patch.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: Joseph Yasi <joe.yasi@gmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203175
Tested-by: Joseph Yasi <joe.yasi@gmail.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 0e09bed..e21b2ff 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5308,13 +5308,8 @@ static void e1000_watchdog_task(struct work_struct *work)
                        /* 8000ES2LAN requires a Rx packet buffer work-around
                         * on link down event; reset the controller to flush
                         * the Rx packet buffer.
-                        *
-                        * If the link is lost the controller stops DMA, but
-                        * if there is queued Tx work it cannot be done.  So
-                        * reset the controller to flush the Tx packet buffers.
                         */
-                       if ((adapter->flags & FLAG_RX_NEEDS_RESTART) ||
-                           e1000_desc_unused(tx_ring) + 1 < tx_ring->count)
+                       if (adapter->flags & FLAG_RX_NEEDS_RESTART)
                                adapter->flags |= FLAG_RESTART_NOW;
                        else
                                pm_schedule_suspend(netdev->dev.parent,
@@ -5337,6 +5332,14 @@ link_up:
        adapter->gotc_old = adapter->stats.gotc;
        spin_unlock(&adapter->stats64_lock);
 
+       /* If the link is lost the controller stops DMA, but
+        * if there is queued Tx work it cannot be done.  So
+        * reset the controller to flush the Tx packet buffers.
+        */
+       if (!netif_carrier_ok(netdev) &&
+           (e1000_desc_unused(tx_ring) + 1 < tx_ring->count))
+               adapter->flags |= FLAG_RESTART_NOW;
+
        /* If reset is necessary, do it outside of interrupt context. */
        if (adapter->flags & FLAG_RESTART_NOW) {
                schedule_work(&adapter->reset_task);