From 082297e61480c4d72ed75b31077e74aca0e7c799 Mon Sep 17 00:00:00 2001
From: Antoine Tenart <antoine.tenart@free-electrons.com>
Date: Mon, 23 Oct 2017 15:24:31 +0200
Subject: [PATCH] net: mvpp2: do not call txq_done from the Tx path when Tx
irqs are used
When Tx IRQs are used, txq_bufs_free() can be called from both the Tx
path and from NAPI poll(). This led to CPU stalls as if these two tasks
(Tx and Poll) are scheduled on two CPUs at the same time, DMA unmapping
operations are done on the same txq buffers.
This patch adds a check not to call txq_done() from the Tx path if Tx
interrupts are used as it does not make sense to do so.
Fixes: edc660fa09e2 ("net: mvpp2: replace TX coalescing interrupts with hrtimer")
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/ethernet/marvell/mvpp2.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
index 3de05a8c468a4..28c6e8a5e1183 100644
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -6499,7 +6499,7 @@ static int mvpp2_tx(struct sk_buff *skb, struct net_device *dev)
}
/* Finalize TX processing */
- if (txq_pcpu->count >= txq->done_pkts_coal)
+ if (!port->has_tx_irqs && txq_pcpu->count >= txq->done_pkts_coal)
mvpp2_txq_done(port, txq, txq_pcpu);
/* Set the timer in case not all frags were processed */