net: stmmac: Let TX and RX interrupts be independently enabled/disabled

By using this mechanism we can get rid of the not so nice method of
scheduling TX NAPI when the RX was scheduled. No bandwidth reduction was
seen with this change.

Changes from v1:
- Remove useless comment (Jakub)
- Do not bind the TX clean to NAPI budget (Jakub)

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 22 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 3299f5bb02e2..d1a22c4fe67b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2069,17 +2069,25 @@ static int stmmac_napi_check(struct stmmac_priv *priv, u32 chan)
 	int status = stmmac_dma_interrupt_status(priv, priv->ioaddr,
 						 &priv->xstats, chan);
 	struct stmmac_channel *ch = &priv->channel[chan];
+	unsigned long flags;
 
 	if ((status & handle_rx) && (chan < priv->plat->rx_queues_to_use)) {
 		if (napi_schedule_prep(&ch->rx_napi)) {
-			stmmac_disable_dma_irq(priv, priv->ioaddr, chan);
+			spin_lock_irqsave(&ch->lock, flags);
+			stmmac_disable_dma_irq(priv, priv->ioaddr, chan, 1, 0);
+			spin_unlock_irqrestore(&ch->lock, flags);
 			__napi_schedule_irqoff(&ch->rx_napi);
-			status |= handle_tx;
 		}
 	}
 
-	if ((status & handle_tx) && (chan < priv->plat->tx_queues_to_use))
-		napi_schedule_irqoff(&ch->tx_napi);
+	if ((status & handle_tx) && (chan < priv->plat->tx_queues_to_use)) {
+		if (napi_schedule_prep(&ch->tx_napi)) {
+			spin_lock_irqsave(&ch->lock, flags);
+			stmmac_disable_dma_irq(priv, priv->ioaddr, chan, 0, 1);
+			spin_unlock_irqrestore(&ch->lock, flags);
+			__napi_schedule_irqoff(&ch->tx_napi);
+		}
+	}
 
 	return status;
 }
@@ -2274,14 +2282,14 @@ static void stmmac_tx_timer(struct timer_list *t)
 
 	ch = &priv->channel[tx_q->queue_index];
 
-	/*
-	 * If NAPI is already running we can miss some events. Let's rearm
-	 * the timer and try again.
-	 */
-	if (likely(napi_schedule_prep(&ch->tx_napi)))
+	if (likely(napi_schedule_prep(&ch->tx_napi))) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&ch->lock, flags);
+		stmmac_disable_dma_irq(priv, priv->ioaddr, ch->index, 0, 1);
+		spin_unlock_irqrestore(&ch->lock, flags);
 		__napi_schedule(&ch->tx_napi);
-	else
-		mod_timer(&tx_q->txtimer, STMMAC_COAL_TIMER(10));
+	}
 }
 
 /**
@@ -3751,8 +3759,14 @@ static int stmmac_napi_poll_rx(struct napi_struct *napi, int budget)
 	priv->xstats.napi_poll++;
 
 	work_done = stmmac_rx(priv, budget, chan);
-	if (work_done < budget && napi_complete_done(napi, work_done))
-		stmmac_enable_dma_irq(priv, priv->ioaddr, chan);
+	if (work_done < budget && napi_complete_done(napi, work_done)) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&ch->lock, flags);
+		stmmac_enable_dma_irq(priv, priv->ioaddr, chan, 1, 0);
+		spin_unlock_irqrestore(&ch->lock, flags);
+	}
+
 	return work_done;
 }
 
@@ -3761,7 +3775,6 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
 	struct stmmac_channel *ch =
 		container_of(napi, struct stmmac_channel, tx_napi);
 	struct stmmac_priv *priv = ch->priv_data;
-	struct stmmac_tx_queue *tx_q;
 	u32 chan = ch->index;
 	int work_done;
 
@@ -3770,15 +3783,12 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget)
 	work_done = stmmac_tx_clean(priv, DMA_TX_SIZE, chan);
 	work_done = min(work_done, budget);
 
-	if (work_done < budget)
-		napi_complete_done(napi, work_done);
+	if (work_done < budget && napi_complete_done(napi, work_done)) {
+		unsigned long flags;
 
-	/* Force transmission restart */
-	tx_q = &priv->tx_queue[chan];
-	if (tx_q->cur_tx != tx_q->dirty_tx) {
-		stmmac_enable_dma_transmission(priv, priv->ioaddr);
-		stmmac_set_tx_tail_ptr(priv, priv->ioaddr, tx_q->tx_tail_addr,
-				       chan);
+		spin_lock_irqsave(&ch->lock, flags);
+		stmmac_enable_dma_irq(priv, priv->ioaddr, chan, 0, 1);
+		spin_unlock_irqrestore(&ch->lock, flags);
 	}
 
 	return work_done;
@@ -4714,6 +4724,7 @@ int stmmac_dvr_probe(struct device *device,
 	for (queue = 0; queue < maxq; queue++) {
 		struct stmmac_channel *ch = &priv->channel[queue];
 
+		spin_lock_init(&ch->lock);
 		ch->priv_data = priv;
 		ch->index = queue;