On 13/07/2026 12:42, Maciej Fijalkowski wrote:
On Sun, Jul 12, 2026 at 02:22:42PM +0100, David Carlier wrote:
When an AF_XDP zero-copy application is killed abruptly, the XSK pool is
torn down but NAPI keeps polling. igc_clean_rx_irq_zc() then returns the
full budget on every poll, so napi_complete_done() never clears
NAPI_STATE_SCHED.
igc_down() calls napi_synchronize() before napi_disable(), so it spins
forever waiting for that bit and the interface never goes down. Drop the
napi_synchronize() and let napi_disable() do the job -- it sets
NAPI_STATE_DISABLE, which forces the stuck poll to complete. Reorder it
ahead of igc_set_queue_napi() so the NAPI mapping is cleared only after
polling has stopped, matching the recent igb fix b1e067240379.
Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy")
Suggested-by: Maciej Fijalkowski <[email protected]>
Cc: [email protected]
Signed-off-by: David Carlier <[email protected]>
Reviewed-by: Maciej Fijalkowski <[email protected]>
This is a mirror of what Alex Dvoretsky did on igb, correct? Did you
reproduce the same issue on your side or is it a blind shot at this
driver?
Regardless, I think it's a correct thing to do, but some clarification
would be nice.
---
drivers/net/ethernet/intel/igc/igc_main.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c
b/drivers/net/ethernet/intel/igc/igc_main.c
index 2c9e2dfd8499..b3883a5a7d7a 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -5352,9 +5352,8 @@ void igc_down(struct igc_adapter *adapter)
for (i = 0; i < adapter->num_q_vectors; i++) {
if (adapter->q_vector[i]) {
- napi_synchronize(&adapter->q_vector[i]->napi);
- igc_set_queue_napi(adapter, i, NULL);
napi_disable(&adapter->q_vector[i]->napi);
+ igc_set_queue_napi(adapter, i, NULL);
}
}
--
2.53.0
Reviewed-by: Dima Ruinskiy <[email protected]>
