From: Suraj Gupta Date: Wed, 21 May 2025 18:16:08 +0000 (+0530) Subject: net: xilinx: axienet: Fix Tx skb circular buffer occupancy check in dmaengine xmit X-Git-Tag: v6.16-rc1~132^2^2~14 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=32374234ab0101881e7d0c6a8ef7ebce566c46c9;p=linux-block.git net: xilinx: axienet: Fix Tx skb circular buffer occupancy check in dmaengine xmit In Dmaengine flow, driver maintains struct skbuf_dma_descriptor rings each element of which corresponds to a skb. In Tx datapath, compare available space in skb ring with number of skbs instead of skb fragments. Replace x * (MAX_SKB_FRAGS) in netif_txq_completed_wake() and netif_txq_maybe_stop() with x * (1 skb) to fix the comparison. Fixes: 6a91b846af85 ("net: axienet: Introduce dmaengine support") Signed-off-by: Suraj Gupta Reviewed-by: Sean Anderson Link: https://patch.msgid.link/20250521181608.669554-1-suraj.gupta2@amd.com Signed-off-by: Paolo Abeni --- diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 054abf283ab3..5f912b27bfd7 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -880,7 +880,7 @@ static void axienet_dma_tx_cb(void *data, const struct dmaengine_result *result) dev_consume_skb_any(skbuf_dma->skb); netif_txq_completed_wake(txq, 1, len, CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX), - 2 * MAX_SKB_FRAGS); + 2); } /** @@ -914,7 +914,7 @@ axienet_start_xmit_dmaengine(struct sk_buff *skb, struct net_device *ndev) dma_dev = lp->tx_chan->device; sg_len = skb_shinfo(skb)->nr_frags + 1; - if (CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX) <= sg_len) { + if (CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX) <= 1) { netif_stop_queue(ndev); if (net_ratelimit()) netdev_warn(ndev, "TX ring unexpectedly full\n"); @@ -964,7 +964,7 @@ axienet_start_xmit_dmaengine(struct sk_buff *skb, struct net_device *ndev) txq = skb_get_tx_queue(lp->ndev, skb); netdev_tx_sent_queue(txq, skb->len); netif_txq_maybe_stop(txq, CIRC_SPACE(lp->tx_ring_head, lp->tx_ring_tail, TX_BD_NUM_MAX), - MAX_SKB_FRAGS + 1, 2 * MAX_SKB_FRAGS); + 1, 2); dmaengine_submit(dma_tx_desc); dma_async_issue_pending(lp->tx_chan);