nfp: correct desc type when header dma len is 4096

When there's only one buffer to dma and its length is 4096, then
only one data descriptor is needed to carry it according to current
descriptor definition. So the descriptor type should be `simple`
instead of `gather`, the latter requires more than one descriptor,
otherwise it'll be dropped by application firmware.

Fixes: c10d12e3dce8 ("nfp: add support for NFDK data path")
Fixes: d9d950490a0a ("nfp: nfdk: implement xdp tx path for NFDK")
Signed-off-by: Yinjun Zhang <yinjun.zhang@corigine.com>
Reviewed-by: Richard Donkin <richard.donkin@corigine.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20221202134646.311108-1-simon.horman@corigine.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c
index 2b427d8ccb2f3f8727c8934b9ca2da99c5142ce8..ccacb6ab6c39f8742c310e1081b3051970618217 100644 (file)
--- a/drivers/net/ethernet/netronome/nfp/nfdk/dp.c
+++ b/drivers/net/ethernet/netronome/nfp/nfdk/dp.c
@@ -282,7 +282,7 @@ netdev_tx_t nfp_nfdk_tx(struct sk_buff *skb, struct net_device *netdev)
        dma_len = skb_headlen(skb);
        if (skb_is_gso(skb))
                type = NFDK_DESC_TX_TYPE_TSO;
-       else if (!nr_frags && dma_len < NFDK_TX_MAX_DATA_PER_HEAD)
+       else if (!nr_frags && dma_len <= NFDK_TX_MAX_DATA_PER_HEAD)
                type = NFDK_DESC_TX_TYPE_SIMPLE;
        else
                type = NFDK_DESC_TX_TYPE_GATHER;
@@ -927,7 +927,7 @@ nfp_nfdk_tx_xdp_buf(struct nfp_net_dp *dp, struct nfp_net_rx_ring *rx_ring,
        dma_len = pkt_len;
        dma_addr = rxbuf->dma_addr + dma_off;
 
-       if (dma_len < NFDK_TX_MAX_DATA_PER_HEAD)
+       if (dma_len <= NFDK_TX_MAX_DATA_PER_HEAD)
                type = NFDK_DESC_TX_TYPE_SIMPLE;
        else
                type = NFDK_DESC_TX_TYPE_GATHER;
@@ -1325,7 +1325,7 @@ nfp_nfdk_ctrl_tx_one(struct nfp_net *nn, struct nfp_net_r_vector *r_vec,
        txbuf = &tx_ring->ktxbufs[wr_idx];
 
        dma_len = skb_headlen(skb);
-       if (dma_len < NFDK_TX_MAX_DATA_PER_HEAD)
+       if (dma_len <= NFDK_TX_MAX_DATA_PER_HEAD)
                type = NFDK_DESC_TX_TYPE_SIMPLE;
        else
                type = NFDK_DESC_TX_TYPE_GATHER;