6.16-stable review patch. If anyone has any objections, please let me know.
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From: Suraj Gupta suraj.gupta2@amd.com
[ Upstream commit fd980bf6e9cdae885105685259421164f843ca55 ]
Submit multiple descriptors in axienet_rx_cb() to fill Rx skb ring. This ensures the ring "catches up" on previously missed allocations.
Increment Rx skb ring head pointer after BD is successfully allocated. Previously, head pointer was incremented before verifying if descriptor is successfully allocated and has valid entries, which could lead to ring state inconsistency if descriptor setup failed.
These changes improve reliability by maintaining adequate descriptor availability and ensuring proper ring buffer state management.
Fixes: 6a91b846af85 ("net: axienet: Introduce dmaengine support") Signed-off-by: Suraj Gupta suraj.gupta2@amd.com Link: https://patch.msgid.link/20250813135559.1555652-1-suraj.gupta2@amd.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 6011d7eae0c7..0d8a05fe541a 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -1160,6 +1160,7 @@ static void axienet_dma_rx_cb(void *data, const struct dmaengine_result *result) struct axienet_local *lp = data; struct sk_buff *skb; u32 *app_metadata; + int i;
skbuf_dma = axienet_get_rx_desc(lp, lp->rx_ring_tail++); skb = skbuf_dma->skb; @@ -1178,7 +1179,10 @@ static void axienet_dma_rx_cb(void *data, const struct dmaengine_result *result) u64_stats_add(&lp->rx_packets, 1); u64_stats_add(&lp->rx_bytes, rx_len); u64_stats_update_end(&lp->rx_stat_sync); - axienet_rx_submit_desc(lp->ndev); + + for (i = 0; i < CIRC_SPACE(lp->rx_ring_head, lp->rx_ring_tail, + RX_BUF_NUM_DEFAULT); i++) + axienet_rx_submit_desc(lp->ndev); dma_async_issue_pending(lp->rx_chan); }
@@ -1457,7 +1461,6 @@ static void axienet_rx_submit_desc(struct net_device *ndev) if (!skbuf_dma) return;
- lp->rx_ring_head++; skb = netdev_alloc_skb(ndev, lp->max_frm_size); if (!skb) return; @@ -1482,6 +1485,7 @@ static void axienet_rx_submit_desc(struct net_device *ndev) skbuf_dma->desc = dma_rx_desc; dma_rx_desc->callback_param = lp; dma_rx_desc->callback_result = axienet_dma_rx_cb; + lp->rx_ring_head++; dmaengine_submit(dma_rx_desc);
return;