bgmac: leave interrupts disabled as long as there is work to do

Always poll rx and tx during NAPI poll instead of relying on the status
of the first interrupt. This prevents bgmac_poll from leaving unfinished
work around until the next IRQ.
In my tests this makes bridging/routing throughput under heavy load more
stable and ensures that no new IRQs arrive as long as bgmac_poll uses up
the entire budget.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c
index b9e02e484d7278410496300160c07672d9896f2a..9c3b2ff33e6308e6838657cc9e1d0b72319abfa6 100644 (file)
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -1109,8 +1109,6 @@ static void bgmac_chip_reset(struct bgmac *bgmac)
        bgmac_phy_init(bgmac);
 
        netdev_reset_queue(bgmac->net_dev);
-
-       bgmac->int_status = 0;
 }
 
 static void bgmac_chip_intrs_on(struct bgmac *bgmac)
@@ -1225,14 +1223,13 @@ static irqreturn_t bgmac_interrupt(int irq, void *dev_id)
        if (!int_status)
                return IRQ_NONE;
 
-       /* Ack */
-       bgmac_write(bgmac, BGMAC_INT_STATUS, int_status);
+       int_status &= ~(BGMAC_IS_TX0 | BGMAC_IS_RX);
+       if (int_status)
+               bgmac_err(bgmac, "Unknown IRQs: 0x%08X\n", int_status);
 
        /* Disable new interrupts until handling existing ones */
        bgmac_chip_intrs_off(bgmac);
 
-       bgmac->int_status = int_status;
-
        napi_schedule(&bgmac->napi);
 
        return IRQ_HANDLED;
@@ -1241,25 +1238,17 @@ static irqreturn_t bgmac_interrupt(int irq, void *dev_id)
 static int bgmac_poll(struct napi_struct *napi, int weight)
 {
        struct bgmac *bgmac = container_of(napi, struct bgmac, napi);
-       struct bgmac_dma_ring *ring;
        int handled = 0;
 
-       if (bgmac->int_status & BGMAC_IS_TX0) {
-               ring = &bgmac->tx_ring[0];
-               bgmac_dma_tx_free(bgmac, ring);
-               bgmac->int_status &= ~BGMAC_IS_TX0;
-       }
+       /* Ack */
+       bgmac_write(bgmac, BGMAC_INT_STATUS, ~0);
 
-       if (bgmac->int_status & BGMAC_IS_RX) {
-               ring = &bgmac->rx_ring[0];
-               handled += bgmac_dma_rx_read(bgmac, ring, weight);
-               bgmac->int_status &= ~BGMAC_IS_RX;
-       }
+       bgmac_dma_tx_free(bgmac, &bgmac->tx_ring[0]);
+       handled += bgmac_dma_rx_read(bgmac, &bgmac->rx_ring[0], weight);
 
-       if (bgmac->int_status) {
-               bgmac_err(bgmac, "Unknown IRQs: 0x%08X\n", bgmac->int_status);
-               bgmac->int_status = 0;
-       }
+       /* Poll again if more events arrived in the meantime */
+       if (bgmac_read(bgmac, BGMAC_INT_STATUS) & (BGMAC_IS_TX0 | BGMAC_IS_RX))
+               return handled;
 
        if (handled < weight) {
                napi_complete(napi);

diff --git a/drivers/net/ethernet/broadcom/bgmac.h b/drivers/net/ethernet/broadcom/bgmac.h
index 5a198d56f3e74b65d3fc8afd3db4d3aeed75c7d6..abd50d128e6c7f263ad2de958f4b9488503f5193 100644 (file)
--- a/drivers/net/ethernet/broadcom/bgmac.h
+++ b/drivers/net/ethernet/broadcom/bgmac.h
@@ -452,7 +452,6 @@ struct bgmac {
 
        /* Int */
        u32 int_mask;
-       u32 int_status;
 
        /* Current MAC state */
        int mac_speed;