6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx>
[ Upstream commit cb47b1f679c4d83a5fa5f1852e472f844e41a3da ]
When an XDP redirect happens before the link is ready, that
transmission will not finish and will timeout, causing an adapter
reset. If the redirects do not stop, the adapter will not stop
resetting.
Wait for the driver to signal that there's a carrier before allowing
transmissions to proceed.
Previous code was relying that when __IGC_DOWN is cleared, the NIC is
ready to transmit as all the queues are ready, what happens is that
the carrier presence will only be signaled later, after the watchdog
workqueue has a chance to run. And during this interval (between
clearing __IGC_DOWN and the watchdog running) if any transmission
happens the timeout is emitted (detected by igc_tx_timeout()) which
causes the reset, with the potential for the infinite loop.
Fixes: 4ff320361092 ("igc: Add support for XDP_REDIRECT action")
Reported-by: Ferenc Fejes <ferenc.fejes@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/netdev/0caf33cf6adb3a5bf137eeaa20e89b167c9986d5.camel@xxxxxxxxxxxx/
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@xxxxxxxxx>
Tested-by: Ferenc Fejes <ferenc.fejes@xxxxxxxxxxxx>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
Tested-by: Naama Meir <naamax.meir@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/intel/igc/igc_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 6f557e843e495..4e23b821c39ba 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -6433,7 +6433,7 @@ static int igc_xdp_xmit(struct net_device *dev, int num_frames,
struct igc_ring *ring;
int i, drops;
- if (unlikely(test_bit(__IGC_DOWN, &adapter->state)))
+ if (unlikely(!netif_carrier_ok(dev)))
return -ENETDOWN;
if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
--
2.40.1
