Commit 32374234 authored by Suraj Gupta's avatar Suraj Gupta Committed by Paolo Abeni
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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: 6a91b846 ("net: axienet: Introduce dmaengine support")
Signed-off-by: default avatarSuraj Gupta <suraj.gupta2@amd.com>
Reviewed-by: default avatarSean Anderson <sean.anderson@linux.dev>
Link: https://patch.msgid.link/20250521181608.669554-1-suraj.gupta2@amd.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent f0b50730

drivers/net/ethernet/xilinx/xilinx_axienet_main.c

+3 −3
Original line number Diff line number Diff line
@@ -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);