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net: bcmgenet: clear status to reduce spurious interrupts

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Since the DMA interrupt status is latched and the DMA servicing can be
polled, it is a good idea to clear the latched status of a DMA interrupt
before performing the service that would be invoked by the interrupt.

This prevents old status from causing spurious interrupts when the
interrupt is unmasked at a later time.

Signed-off-by: Doug Berger <opendmb@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Doug Berger 2017-03-13 17:41:37 -07:00 committed by David S. Miller
parent b1ec494dee
commit d5810ca325
1 changed files with 20 additions and 1 deletions
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21
drivers/net/ethernet/broadcom/genet/bcmgenet.c
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@ -1174,6 +1174,14 @@ static unsigned int __bcmgenet_tx_reclaim(struct net_device *dev,
unsigned int txbds_ready;
unsigned int txbds_processed = 0;
/* Clear status before servicing to reduce spurious interrupts */
if (ring->index == DESC_INDEX)
bcmgenet_intrl2_0_writel(priv, UMAC_IRQ_TXDMA_DONE,
INTRL2_CPU_CLEAR);
else
bcmgenet_intrl2_1_writel(priv, (1 << ring->index),
INTRL2_CPU_CLEAR);
/* Compute how many buffers are transmitted since last xmit call */
c_index = bcmgenet_tdma_ring_readl(priv, ring->index, TDMA_CONS_INDEX)
& DMA_C_INDEX_MASK;
@ -1584,10 +1592,21 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_rx_ring *ring,
unsigned long dma_flag;
int len;
unsigned int rxpktprocessed = 0, rxpkttoprocess;
unsigned int p_index;
unsigned int p_index, mask;
unsigned int discards;
unsigned int chksum_ok = 0;
/* Clear status before servicing to reduce spurious interrupts */
if (ring->index == DESC_INDEX) {
bcmgenet_intrl2_0_writel(priv, UMAC_IRQ_RXDMA_DONE,
INTRL2_CPU_CLEAR);
} else {
mask = 1 << (UMAC_IRQ1_RX_INTR_SHIFT + ring->index);
bcmgenet_intrl2_1_writel(priv,
mask,
INTRL2_CPU_CLEAR);
}
p_index = bcmgenet_rdma_ring_readl(priv, ring->index, RDMA_PROD_INDEX);
discards = (p_index >> DMA_P_INDEX_DISCARD_CNT_SHIFT) &