6.1-stable review patch. If anyone has any objections, please let me know.
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From: Michal Kubiak michal.kubiak@intel.com
[ Upstream commit ec145a18687fec8dd97eeb4f30057fa4debef577 ]
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 shannon.nelson@amd.com Tested-by: Chandan Kumar Rout chandanx.rout@intel.com (A Contingent Worker at Intel) Signed-off-by: Michal Kubiak michal.kubiak@intel.com Signed-off-by: Maciej Fijalkowski maciej.fijalkowski@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b917f271cdac1..61e4730bba59e 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.c +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c @@ -937,6 +937,10 @@ 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; + budget = ICE_DESC_UNUSED(xdp_ring); budget = min_t(u16, budget, ICE_RING_QUARTER(xdp_ring));
@@ -980,7 +984,7 @@ 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)) return -ENETDOWN;
if (!ice_is_xdp_ena_vsi(vsi))