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
>
