netdev - [PATCH v2 4/4] net: lantiq: Disable IRQs only if NAPI gets scheduled

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Date:   Sat, 12 Sep 2020 21:36:29 +0200
From:   Hauke Mehrtens <hauke@...ke-m.de>
To:     davem@...emloft.net
Cc:     kuba@...nel.org, netdev@...r.kernel.org,
        martin.blumenstingl@...glemail.com, eric.dumazet@...il.com,
        Hauke Mehrtens <hauke@...ke-m.de>
Subject: [PATCH v2 4/4] net: lantiq: Disable IRQs only if NAPI gets scheduled

The napi_schedule() call will only schedule the NAPI if it is not
already running. To make sure that we do not deactivate interrupts
without scheduling NAPI only deactivate the interrupts in case NAPI also
gets scheduled.

Signed-off-by: Hauke Mehrtens <hauke@...ke-m.de>
---
 drivers/net/ethernet/lantiq_xrx200.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
index abee7d61074c..635ff3a5dcfb 100644
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -345,10 +345,12 @@ static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
 {
 	struct xrx200_chan *ch = ptr;
 
-	ltq_dma_disable_irq(&ch->dma);
-	ltq_dma_ack_irq(&ch->dma);
+	if (napi_schedule_prep(&ch->napi)) {
+		__napi_schedule(&ch->napi);
+		ltq_dma_disable_irq(&ch->dma);
+	}
 
-	napi_schedule(&ch->napi);
+	ltq_dma_ack_irq(&ch->dma);
 
 	return IRQ_HANDLED;
 }
-- 
2.20.1