On Wed, 22 Jun 2022 17:05:44 +0800 Biao Huang wrote: > + if (rx || tx) { > + spin_lock_irqsave(&priv->lock, flags); > + /* mask Rx and TX Complete interrupt */ > + mtk_star_disable_dma_irq(priv, rx, tx); > + spin_unlock_irqrestore(&priv->lock, flags); You do _irqsave / _irqrestore here > + if (rx) > + __napi_schedule_irqoff(&priv->rx_napi); > + if (tx) > + __napi_schedule_irqoff(&priv->tx_napi); Yet assume _irqoff here. So can this be run from non-IRQ context or not? > - if (mtk_star_ring_full(ring)) > + if (unlikely(mtk_star_tx_ring_avail(ring) < MAX_SKB_FRAGS + 1)) > netif_stop_queue(ndev); Please look around other drivers (like ixgbe) and copy the way they handle safe stopping of the queues. You need to add some barriers and re-check after disabling. > - spin_unlock_bh(&priv->lock); > - > mtk_star_dma_resume_tx(priv); > > return NETDEV_TX_OK; > + while ((entry != head) && (count < MTK_STAR_RING_NUM_DESCS - 1)) { > Parenthesis unnecessary, so is the empty line after the while (). > ret = mtk_star_tx_complete_one(priv); > if (ret < 0) > break; > + > + count++; > + pkts_compl++; > + bytes_compl += ret; > + entry = ring->tail; > } > > + __netif_tx_lock_bh(netdev_get_tx_queue(priv->ndev, 0)); > netdev_completed_queue(ndev, pkts_compl, bytes_compl); > + __netif_tx_unlock_bh(netdev_get_tx_queue(priv->ndev, 0)); what are you taking this lock for? > - if (wake && netif_queue_stopped(ndev)) > + if (unlikely(netif_queue_stopped(ndev)) && > + (mtk_star_tx_ring_avail(ring) > MTK_STAR_TX_THRESH)) > netif_wake_queue(ndev); > > - spin_unlock(&priv->lock); > + if (napi_complete(napi)) { > + spin_lock_irqsave(&priv->lock, flags); > + mtk_star_enable_dma_irq(priv, false, true); > + spin_unlock_irqrestore(&priv->lock, flags); > + } > + > + return 0; > } > @@ -1475,6 +1514,7 @@ static int mtk_star_set_timing(struct mtk_star_priv *priv) > > return regmap_write(priv->regs, MTK_STAR_REG_TEST0, delay_val); > } > + > static int mtk_star_probe(struct platform_device *pdev) > { > struct device_node *of_node; spurious whitespace change