When igb_xdp_setup() transitions between XDP and non-XDP mode on a
running device, it calls igb_close() followed by igb_open(). During
this window the adapter is down while trans_start still contains the
timestamp from before igb_close(), so the TX watchdog can fire a
spurious timeout.
The resulting schedule_work(&adapter->reset_task) races with the
igb_open() path: the reset task may run while the device is being
brought back up, or immediately after, causing unexpected ring
reinitialisation and register writes.
Fix this by checking __IGB_DOWN at the top of igb_tx_timeout(). A
reset is unnecessary because the device will be fully reinitialised
by the subsequent igb_open().
Fixes: 9cbc948b5a20 ("igb: add XDP support")
Cc: [email protected]
Signed-off-by: Alex Dvoretsky <[email protected]>
---
drivers/net/ethernet/intel/igb/igb_main.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
b/drivers/net/ethernet/intel/igb/igb_main.c
index 223a10cae4a9..ddb7ce9e97bf 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -6651,6 +6651,10 @@ static void igb_tx_timeout(struct net_device *netdev,
unsigned int __always_unus
struct igb_adapter *adapter = netdev_priv(netdev);
struct e1000_hw *hw = &adapter->hw;
+ /* Ignore timeout if the adapter is going down. */
+ if (test_bit(__IGB_DOWN, &adapter->state))
+ return;
+
/* Do the reset outside of interrupt context */
adapter->tx_timeout_count++;
--
2.51.0
