6.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Lorenzo Bianconi lorenzo@kernel.org
[ Upstream commit bd5afca115f181c85f992d42a57cd497bc823ccb ]
Completion napi can free out-of-order tx descriptors if hw QoS is enabled and packets with different priority are queued to same DMA ring. Take into account possible out-of-order reports checking if the tx queue is full using circular buffer head/tail pointer instead of the number of queued packets.
Fixes: 23020f0493270 ("net: airoha: Introduce ethernet support for EN7581 SoC") Suggested-by: Simon Horman horms@kernel.org Signed-off-by: Lorenzo Bianconi lorenzo@kernel.org Reviewed-by: Simon Horman horms@kernel.org Link: https://patch.msgid.link/20251012-airoha-tx-busy-queue-v2-1-a600b08bab2d@ker... Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/airoha/airoha_eth.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index 6d23c5c049b9a..ffb10c758c293 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -1872,6 +1872,20 @@ static u32 airoha_get_dsa_tag(struct sk_buff *skb, struct net_device *dev) #endif }
+static bool airoha_dev_tx_queue_busy(struct airoha_queue *q, u32 nr_frags) +{ + u32 tail = q->tail <= q->head ? q->tail + q->ndesc : q->tail; + u32 index = q->head + nr_frags; + + /* completion napi can free out-of-order tx descriptors if hw QoS is + * enabled and packets with different priorities are queued to the same + * DMA ring. Take into account possible out-of-order reports checking + * if the tx queue is full using circular buffer head/tail pointers + * instead of the number of queued packets. + */ + return index >= tail; +} + static netdev_tx_t airoha_dev_xmit(struct sk_buff *skb, struct net_device *dev) { @@ -1925,7 +1939,7 @@ static netdev_tx_t airoha_dev_xmit(struct sk_buff *skb, txq = netdev_get_tx_queue(dev, qid); nr_frags = 1 + skb_shinfo(skb)->nr_frags;
- if (q->queued + nr_frags > q->ndesc) { + if (airoha_dev_tx_queue_busy(q, nr_frags)) { /* not enough space in the queue */ netif_tx_stop_queue(txq); spin_unlock_bh(&q->lock);