netdev - [PATCH net-next] net: systemport: Do not block interrupts in TX reclaim

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Date:   Fri, 24 Jan 2020 15:59:30 -0800
From:   Florian Fainelli <f.fainelli@...il.com>
To:     netdev@...r.kernel.org
Cc:     kuba@...nel.org, edumazet@...gle.com,
        Florian Fainelli <f.fainelli@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        bcm-kernel-feedback-list@...adcom.com (open list:BROADCOM SYSTEMPORT
        ETHERNET DRIVER), linux-kernel@...r.kernel.org (open list)
Subject: [PATCH net-next] net: systemport: Do not block interrupts in TX reclaim

There is no need to disable interrupts with a spin_lock_irqsave() in
bcm_sysport_tx_poll() since we are in softIRQ context already. Leave
interrupts enabled, thus giving a chance for the RX interrupts to be
processed.

This now makes bcm_sysport_tx_reclaim() equivalent to
bcm_sysport_tx_clean(), thus remove the former, and make
bcm_sysport_tx_reclaim_all() to use the latter.

Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
---
 drivers/net/ethernet/broadcom/bcmsysport.c | 30 ++++++----------------
 1 file changed, 8 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index f07ac0e0af59..dfff0657ce8f 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -925,26 +925,6 @@ static unsigned int __bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
 	return pkts_compl;
 }
 
-/* Locked version of the per-ring TX reclaim routine */
-static unsigned int bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
-					   struct bcm_sysport_tx_ring *ring)
-{
-	struct netdev_queue *txq;
-	unsigned int released;
-	unsigned long flags;
-
-	txq = netdev_get_tx_queue(priv->netdev, ring->index);
-
-	spin_lock_irqsave(&ring->lock, flags);
-	released = __bcm_sysport_tx_reclaim(priv, ring);
-	if (released)
-		netif_tx_wake_queue(txq);
-
-	spin_unlock_irqrestore(&ring->lock, flags);
-
-	return released;
-}
-
 /* Locked version of the per-ring TX reclaim, but does not wake the queue */
 static void bcm_sysport_tx_clean(struct bcm_sysport_priv *priv,
 				 struct bcm_sysport_tx_ring *ring)
@@ -960,9 +940,15 @@ static int bcm_sysport_tx_poll(struct napi_struct *napi, int budget)
 {
 	struct bcm_sysport_tx_ring *ring =
 		container_of(napi, struct bcm_sysport_tx_ring, napi);
+	struct bcm_sysport_priv *priv = ring->priv;
 	unsigned int work_done = 0;
 
-	work_done = bcm_sysport_tx_reclaim(ring->priv, ring);
+	spin_lock(&ring->lock);
+	work_done = __bcm_sysport_tx_reclaim(priv, ring);
+	if (work_done)
+		netif_tx_wake_queue(netdev_get_tx_queue(priv->netdev,
+							ring->index));
+	spin_unlock(&ring->lock);
 
 	if (work_done == 0) {
 		napi_complete(napi);
@@ -984,7 +970,7 @@ static void bcm_sysport_tx_reclaim_all(struct bcm_sysport_priv *priv)
 	unsigned int q;
 
 	for (q = 0; q < priv->netdev->num_tx_queues; q++)
-		bcm_sysport_tx_reclaim(priv, &priv->tx_rings[q]);
+		bcm_sysport_tx_clean(priv, &priv->tx_rings[q]);
 }
 
 static int bcm_sysport_poll(struct napi_struct *napi, int budget)
-- 
2.17.1