net: systemport: Clear status to reduce spurious interrupts

Do something similar to commit d5810ca3252a ("net: bcmgenet: clear
status to reduce spurious interrupts") and clear interrupts right before
servicing them. This reduces the number of interrupts by 10K
interrupts/sec for a TX TCP session 1Gbits/sec.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index 986fb05529fc0cfe6193e7f52ca604dd623a61cd..c915bcfae0af6627850e3e988979fe12f1661ebb 100644 (file)
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -669,6 +669,9 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
        u16 len, status;
        struct bcm_rsb *rsb;
 
+       /* Clear status before servicing to reduce spurious interrupts */
+       intrl2_0_writel(priv, INTRL2_0_RDMA_MBDONE, INTRL2_CPU_CLEAR);
+
        /* Determine how much we should process since last call, SYSTEMPORT Lite
         * groups the producer and consumer indexes into the same 32-bit
         * which we access using RDMA_CONS_INDEX
@@ -814,6 +817,13 @@ static unsigned int __bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
        struct bcm_sysport_cb *cb;
        u32 hw_ind;
 
+       /* Clear status before servicing to reduce spurious interrupts */
+       if (!ring->priv->is_lite)
+               intrl2_1_writel(ring->priv, BIT(ring->index), INTRL2_CPU_CLEAR);
+       else
+               intrl2_0_writel(ring->priv, BIT(ring->index +
+                               INTRL2_0_TDMA_MBDONE_SHIFT), INTRL2_CPU_CLEAR);
+
        /* Compute how many descriptors have been processed since last call */
        hw_ind = tdma_readl(priv, TDMA_DESC_RING_PROD_CONS_INDEX(ring->index));
        c_index = (hw_ind >> RING_CONS_INDEX_SHIFT) & RING_CONS_INDEX_MASK;