[PATCH AUTOSEL 4.19 027/158] Revert "e1000e: fix cyclic resets at link up with active tx"

Sasha Levin
2019-07-15T14:19:32Z

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

[ Upstream commit caff422ea81e144842bc44bab408d85ac449377b ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/e1000e/netdev.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 8cd339c92c1a..31ef42a031f2 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5286,13 +5286,8 @@ 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,
@@ -5315,6 +5310,14 @@ static void e1000_watchdog_task(struct work_struct *work)
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);
--
2.20.1