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Commit 76d94b23 authored by Tomoya's avatar Tomoya Committed by David S. Miller
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pch_can: Add flow control processing 



Currently, there is no flow control processing.
Thus, Add flow control processing as
when there is no empty of tx buffer,
netif_stop_queue is called.
When there is empty buffer, netif_wake_queue is called.

Signed-off-by: default avatarTomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 249fab77

drivers/net/can/pch_can.c

+12 −19
Original line number Diff line number Diff line
@@ -102,6 +102,10 @@ 


#define PCH_FIFO_THRESH		16



/* TxRqst2 show status of MsgObjNo.17~32 */

#define PCH_TREQ2_TX_MASK	(((1 << PCH_TX_OBJ_NUM) - 1) <<\

							(PCH_RX_OBJ_END - 16))



enum pch_ifreg {

	PCH_RX_IFREG,

	PCH_TX_IFREG,
@@ -871,6 +875,8 @@ static int pch_can_rx_poll(struct napi_struct *napi, int quota) 
			dlc = 8;

		stats->tx_bytes += dlc;

		stats->tx_packets++;

		if (int_stat == PCH_TX_OBJ_END)

			netif_wake_queue(ndev);

	}



	int_stat = pch_can_int_pending(priv);
@@ -1009,18 +1015,6 @@ static int pch_close(struct net_device *ndev) 
	return 0;

}



static int pch_get_msg_obj_sts(struct net_device *ndev, u32 obj_id)

{

	u32 buffer_status = 0;

	struct pch_can_priv *priv = netdev_priv(ndev);



	/* Getting the message object status. */

	buffer_status = (u32) pch_can_get_buffer_status(priv);



	return buffer_status & obj_id;

}





static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)

{

	int i, j;
@@ -1031,17 +1025,16 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev) 
	if (can_dropped_invalid_skb(ndev, skb))

		return NETDEV_TX_OK;



	if (priv->tx_obj == PCH_TX_OBJ_END) { /* Point tail Obj */

		while (pch_get_msg_obj_sts(ndev, (((1 << PCH_TX_OBJ_NUM)-1) <<

					   PCH_RX_OBJ_NUM)))

			udelay(500);

	if (priv->tx_obj == PCH_TX_OBJ_END) {

		if (ioread32(&priv->regs->treq2) & PCH_TREQ2_TX_MASK)

			netif_stop_queue(ndev);



		priv->tx_obj = PCH_TX_OBJ_START; /* Point head of Tx Obj ID */

		tx_buffer_avail = priv->tx_obj; /* Point Tail of Tx Obj */

		tx_buffer_avail = priv->tx_obj;

		priv->tx_obj = PCH_TX_OBJ_START;

	} else {

		tx_buffer_avail = priv->tx_obj;

	}

		priv->tx_obj++;

	}



	/* Reading the Msg Obj from the Msg RAM to the Interface register. */

	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[1].cmask);