From: Maciej Fijalkowski <[email protected]> Date: Tue, 4 Jun 2024 15:21:48 +0200
> From: Michal Kubiak <[email protected]> > > Address a scenario in which XSK ZC Tx produces descriptors to XDP Tx > ring when link is either not yet fully initialized or process of > stopping the netdev has already started. To avoid this, add checks > against carrier readiness in ice_xsk_wakeup() and in ice_xmit_zc(). > One could argue that bailing out early in ice_xsk_wakeup() would be > sufficient but given the fact that we produce Tx descriptors on behalf > of NAPI that is triggered for Rx traffic, the latter is also needed. > > Bringing link up is an asynchronous event executed within > ice_service_task so even though interface has been brought up there is > still a time frame where link is not yet ok. > > Without this patch, when AF_XDP ZC Tx is used simultaneously with stack > Tx, Tx timeouts occur after going through link flap (admin brings > interface down then up again). HW seem to be unable to transmit > descriptor to the wire after HW tail register bump which in turn causes > bit __QUEUE_STATE_STACK_XOFF to be set forever as > netdev_tx_completed_queue() sees no cleaned bytes on the input. > > Fixes: 126cdfe1007a ("ice: xsk: Improve AF_XDP ZC Tx and use batching API") > Fixes: 2d4238f55697 ("ice: Add support for AF_XDP") > Reviewed-by: Shannon Nelson <[email protected]> > Tested-by: Chandan Kumar Rout <[email protected]> (A Contingent Worker > at Intel) > Signed-off-by: Michal Kubiak <[email protected]> > Signed-off-by: Maciej Fijalkowski <[email protected]> > --- > drivers/net/ethernet/intel/ice/ice_xsk.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c > b/drivers/net/ethernet/intel/ice/ice_xsk.c > index 2015f66b0cf9..1bd4b054dd80 100644 > --- a/drivers/net/ethernet/intel/ice/ice_xsk.c > +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c > @@ -1048,6 +1048,10 @@ bool ice_xmit_zc(struct ice_tx_ring *xdp_ring) > > ice_clean_xdp_irq_zc(xdp_ring); > > + if (!netif_carrier_ok(xdp_ring->vsi->netdev) || > + !netif_running(xdp_ring->vsi->netdev)) > + return true; Why is it checked after clean_xdp_irq_zc()? Also, unlikely()? > + > budget = ICE_DESC_UNUSED(xdp_ring); > budget = min_t(u16, budget, ICE_RING_QUARTER(xdp_ring)); > > @@ -1091,7 +1095,7 @@ ice_xsk_wakeup(struct net_device *netdev, u32 queue_id, > struct ice_vsi *vsi = np->vsi; > struct ice_tx_ring *ring; > > - if (test_bit(ICE_VSI_DOWN, vsi->state)) > + if (test_bit(ICE_VSI_DOWN, vsi->state) || !netif_carrier_ok(netdev)) Same for unlikely()? > return -ENETDOWN; > > if (!ice_is_xdp_ena_vsi(vsi)) Thanks, Olek
