From 0ec1713009c5cc24244c918def1cd14080be27e3 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Mon, 28 Mar 2022 16:21:22 +0200 Subject: [PATCH] ice: xsk: Stop Rx processing when ntc catches ntu This can happen with big budget values and some breakage of re-filling descriptors as we do not clear the entry that ntu is pointing at the end of ice_alloc_rx_bufs_zc. So if ntc is at ntu then it might be the case that status_error0 has an old, uncleared value and ntc would go over with processing which would result in false results. Break Rx loop when ntc == ntu to avoid broken behavior. Fixes: 3876ff525de7 ("ice: xsk: Handle SW XDP ring wrap and bump tail more often") Signed-off-by: Maciej Fijalkowski Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220328142123.170157-4-maciej.fijalkowski@intel.com --- drivers/net/ethernet/intel/ice/ice_xsk.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c index 51427cb4971a..dfbcaf08520e 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.c +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c @@ -608,6 +608,9 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget) */ dma_rmb(); + if (unlikely(rx_ring->next_to_clean == rx_ring->next_to_use)) + break; + xdp = *ice_xdp_buf(rx_ring, rx_ring->next_to_clean); size = le16_to_cpu(rx_desc->wb.pkt_len) & -- 2.20.1