[PATCH 07/11] net: calxedaxgmac: enable interrupts after napi_enable

From: Rob Herring
Date: Mon Aug 26 2013 - 18:46:16 EST


From: Rob Herring <rob.herring@xxxxxxxxxxx>

Fix a race condition where the interrupt handler may have called
napi_schedule before napi_enable is called. This would disable interrupts
and never actually schedule napi to run.

Reported-by: Lennert Buytenhek <buytenh@xxxxxxxxxxxxxx>
Signed-off-by: Rob Herring <rob.herring@xxxxxxxxxxx>
---
drivers/net/ethernet/calxeda/xgmac.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/calxeda/xgmac.c b/drivers/net/ethernet/calxeda/xgmac.c
index cd5872c..385eca0 100644
--- a/drivers/net/ethernet/calxeda/xgmac.c
+++ b/drivers/net/ethernet/calxeda/xgmac.c
@@ -962,9 +962,7 @@ static int xgmac_hw_init(struct net_device *dev)
DMA_BUS_MODE_FB | DMA_BUS_MODE_ATDS | DMA_BUS_MODE_AAL;
writel(value, ioaddr + XGMAC_DMA_BUS_MODE);

- /* Enable interrupts */
- writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_STATUS);
- writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_INTR_ENA);
+ writel(0, ioaddr + XGMAC_DMA_INTR_ENA);

/* Mask power mgt interrupt */
writel(XGMAC_INT_STAT_PMTIM, ioaddr + XGMAC_INT_STAT);
@@ -1032,6 +1030,10 @@ static int xgmac_open(struct net_device *dev)
napi_enable(&priv->napi);
netif_start_queue(dev);

+ /* Enable interrupts */
+ writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_STATUS);
+ writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_INTR_ENA);
+
return 0;
}

--
1.8.1.2

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