Merge branch 'nps_enet_fixes'

Noam Camus says:

====================
*** nps_enet fixups ***

Change v2
TX done is handled back with NAPI poll.

Change v1
This patch set is a bunch of fixes to make nps_enet work correctly with
all platforms, i.e. real device, emulation system, and simulation system.
The main trigger for this patch set was that in our emulation system
the TX end interrupt is "edge-sensitive" and therefore we cannot use the
cause register since it is not sticky.
Also:
TX is handled during HW interrupt context and not NAPI job.
race with TX done was fixed.
added acknowledge for TX when device is "level sensitive".
enable drop of control frames which is not needed for regular usage.

So most of this patch set is about TX handling, which is now more complete.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ezchip/nps_enet.c

@@ -150,6 +150,9 @@ static void nps_enet_tx_handler(struct net_device *ndev)
 	if (!priv->tx_packet_sent || tx_ctrl.ct)
 		return;
 
+	/* Ack Tx ctrl register */
+	nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, 0);
+
 	/* Check Tx transmit error */
 	if (unlikely(tx_ctrl.et)) {
 		ndev->stats.tx_errors++;
@@ -158,11 +161,7 @@ static void nps_enet_tx_handler(struct net_device *ndev)
 		ndev->stats.tx_bytes += tx_ctrl.nt;
 	}
 
-	if (priv->tx_skb) {
 	dev_kfree_skb(priv->tx_skb);
-		priv->tx_skb = NULL;
-	}
-
 	priv->tx_packet_sent = false;
 
 	if (netif_queue_stopped(ndev))
@@ -180,15 +179,16 @@ static int nps_enet_poll(struct napi_struct *napi, int budget)
 {
 	struct net_device *ndev = napi->dev;
 	struct nps_enet_priv *priv = netdev_priv(ndev);
-	struct nps_enet_buf_int_enable buf_int_enable;
 	u32 work_done;
 
-	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) {
+		struct nps_enet_buf_int_enable buf_int_enable;
+
 		napi_complete(napi);
+		buf_int_enable.rx_rdy = NPS_ENET_ENABLE;
+		buf_int_enable.tx_done = NPS_ENET_ENABLE;
 		nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
 				 buf_int_enable.value);
 	}
@@ -211,12 +211,13 @@ 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_buf_int_cause buf_int_cause;
+	struct nps_enet_rx_ctl rx_ctrl;
+	struct nps_enet_tx_ctl tx_ctrl;
 
-	buf_int_cause.value =
-			nps_enet_reg_get(priv, NPS_ENET_REG_BUF_INT_CAUSE);
+	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);
 
-	if (buf_int_cause.tx_done || buf_int_cause.rx_rdy)
+	if ((!tx_ctrl.ct && priv->tx_packet_sent) || rx_ctrl.cr)
 		if (likely(napi_schedule_prep(&priv->napi))) {
 			nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
 			__napi_schedule(&priv->napi);
@@ -307,11 +308,8 @@ static void nps_enet_hw_enable_control(struct net_device *ndev)
 
 	/* Discard Packets bigger than max frame length */
 	max_frame_length = ETH_HLEN + ndev->mtu + ETH_FCS_LEN;
-	if (max_frame_length <= NPS_ENET_MAX_FRAME_LENGTH) {
+	if (max_frame_length <= NPS_ENET_MAX_FRAME_LENGTH)
 		ge_mac_cfg_3->max_len = max_frame_length;
-		nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_3,
-				 ge_mac_cfg_3->value);
-	}
 
 	/* Enable interrupts */
 	buf_int_enable.rx_rdy = NPS_ENET_ENABLE;
@@ -339,11 +337,14 @@ static void nps_enet_hw_enable_control(struct net_device *ndev)
 	ge_mac_cfg_0.tx_fc_en = NPS_ENET_ENABLE;
 	ge_mac_cfg_0.rx_fc_en = NPS_ENET_ENABLE;
 	ge_mac_cfg_0.tx_fc_retr = NPS_ENET_GE_MAC_CFG_0_TX_FC_RETR;
+	ge_mac_cfg_3->cf_drop = NPS_ENET_ENABLE;
 
 	/* Enable Rx and Tx */
 	ge_mac_cfg_0.rx_en = NPS_ENET_ENABLE;
 	ge_mac_cfg_0.tx_en = NPS_ENET_ENABLE;
 
+	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_3,
+			 ge_mac_cfg_3->value);
 	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0,
 			 ge_mac_cfg_0.value);
 }
@@ -527,10 +528,10 @@ static netdev_tx_t nps_enet_start_xmit(struct sk_buff *skb,
 	/* This driver handles one frame at a time  */
 	netif_stop_queue(ndev);
 
-	nps_enet_send_frame(ndev, skb);
-
 	priv->tx_skb = skb;
 
+	nps_enet_send_frame(ndev, skb);
+
 	return NETDEV_TX_OK;
 }
 

drivers/net/ethernet/ezchip/nps_enet.h

@@ -36,7 +36,6 @@
 #define NPS_ENET_REG_RX_CTL		0x810
 #define NPS_ENET_REG_RX_BUF		0x818
 #define NPS_ENET_REG_BUF_INT_ENABLE	0x8C0
-#define NPS_ENET_REG_BUF_INT_CAUSE	0x8C4
 #define NPS_ENET_REG_GE_MAC_CFG_0	0x1000
 #define NPS_ENET_REG_GE_MAC_CFG_1	0x1004
 #define NPS_ENET_REG_GE_MAC_CFG_2	0x1008
@@ -108,25 +107,6 @@ struct nps_enet_buf_int_enable {
 	};
 };
 
-/* Interrupt cause for data buffer events register */
-struct nps_enet_buf_int_cause {
-	union {
-		/* tx_done: Interrupt in the case when current frame was
-		 *          read from TX buffer.
-		 * rx_rdy:  Interrupt in the case when new frame is ready
-		 *          in RX buffer.
-		 */
-		struct {
-			u32
-			__reserved:30,
-			tx_done:1,
-			rx_rdy:1;
-		};
-
-		u32 value;
-	};
-};
-
 /* Gbps Eth MAC Configuration 0 register */
 struct nps_enet_ge_mac_cfg_0 {
 	union {