[net-next 03/15] e1000e: Make speed detection on hotplugging cable more reliable

[Jeff Kirsher]

From: Kai-Heng Feng <kai.heng.f...@canonical.com>

After hot plugging an 1Gbps Ethernet cable with 1Gbps link partner, the
MII_BMSR may report 10Mbps, renders the network rather slow.

The issue has much lower fail rate after commit 59653e6497d1 ("e1000e:
Make watchdog use delayed work"), which essentially introduces some
delay before running the watchdog task.

But there's still a chance that the hot plugging event and the queued
watchdog task gets run at the same time, then the original issue can be
observed once again.

So let's use mod_delayed_work() to add a deterministic 1 second delay
before running watchdog task, after an interrupt.

Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com>
Tested-by: Aaron Brown <aaron.f.br...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c 
b/drivers/net/ethernet/intel/e1000e/netdev.c
index 8a3f035c3a5f..d7d56e42a6aa 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -1780,8 +1780,8 @@ static irqreturn_t e1000_intr_msi(int __always_unused 
irq, void *data)
                }
                /* guard against interrupt when we're going down */
                if (!test_bit(__E1000_DOWN, &adapter->state))
-                       queue_delayed_work(adapter->e1000_workqueue,
-                                          &adapter->watchdog_task, 1);
+                       mod_delayed_work(adapter->e1000_workqueue,
+                                        &adapter->watchdog_task, HZ);
        }
 
        /* Reset on uncorrectable ECC error */
@@ -1861,8 +1861,8 @@ static irqreturn_t e1000_intr(int __always_unused irq, 
void *data)
                }
                /* guard against interrupt when we're going down */
                if (!test_bit(__E1000_DOWN, &adapter->state))
-                       queue_delayed_work(adapter->e1000_workqueue,
-                                          &adapter->watchdog_task, 1);
+                       mod_delayed_work(adapter->e1000_workqueue,
+                                        &adapter->watchdog_task, HZ);
        }
 
        /* Reset on uncorrectable ECC error */
@@ -1907,8 +1907,8 @@ static irqreturn_t e1000_msix_other(int __always_unused 
irq, void *data)
                hw->mac.get_link_status = true;
                /* guard against interrupt when we're going down */
                if (!test_bit(__E1000_DOWN, &adapter->state))
-                       queue_delayed_work(adapter->e1000_workqueue,
-                                          &adapter->watchdog_task, 1);
+                       mod_delayed_work(adapter->e1000_workqueue,
+                                        &adapter->watchdog_task, HZ);
        }
 
        if (!test_bit(__E1000_DOWN, &adapter->state))
-- 
2.21.0