[v1 2/6] NET: nps_enet: reduce processing latency.

From: Noam Camus
Date: Mon Aug 17 2015 - 02:00:46 EST


From: Noam Camus <noamc@xxxxxxxxxx>

TX handler is minimalistic and there is no need to schedule
a NAPI job.
Tx done will be processed during hardware interrupt context.

Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
---
drivers/net/ethernet/ezchip/nps_enet.c | 17 ++++++++++-------
1 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ezchip/nps_enet.c b/drivers/net/ethernet/ezchip/nps_enet.c
index 0e652b4..af72181 100644
--- a/drivers/net/ethernet/ezchip/nps_enet.c
+++ b/drivers/net/ethernet/ezchip/nps_enet.c
@@ -159,7 +159,7 @@ static void nps_enet_tx_handler(struct net_device *ndev)
}

if (priv->tx_skb) {
- dev_kfree_skb(priv->tx_skb);
+ dev_kfree_skb_irq(priv->tx_skb);
priv->tx_skb = NULL;
}

@@ -185,7 +185,6 @@ static int nps_enet_poll(struct napi_struct *napi, int budget)

buf_int_enable.rx_rdy = NPS_ENET_ENABLE;
buf_int_enable.tx_done = NPS_ENET_ENABLE;
- nps_enet_tx_handler(ndev);
work_done = nps_enet_rx_handler(ndev);
if (work_done < budget) {
napi_complete(napi);
@@ -212,14 +211,18 @@ static irqreturn_t nps_enet_irq_handler(s32 irq, void *dev_instance)
struct net_device *ndev = dev_instance;
struct nps_enet_priv *priv = netdev_priv(ndev);
struct nps_enet_rx_ctl rx_ctrl;
- struct nps_enet_tx_ctl tx_ctrl;

- rx_ctrl.value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
- tx_ctrl.value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
+ nps_enet_tx_handler(ndev);

- if ((!tx_ctrl.ct && priv->tx_packet_sent) || rx_ctrl.cr)
+ rx_ctrl.value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
+ if (rx_ctrl.cr)
if (likely(napi_schedule_prep(&priv->napi))) {
- nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
+ struct nps_enet_buf_int_enable buf_int_enable;
+
+ buf_int_enable.rx_rdy = NPS_ENET_DISABLE;
+ buf_int_enable.tx_done = NPS_ENET_ENABLE;
+ nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
+ buf_int_enable.value);
__napi_schedule(&priv->napi);
}

--
1.7.1

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