[PATCH net-next-2.6 v9 01/20] pch_can: Add flow control processing

Tomoya MORINAGA
2010-12-13T06:21:59Z

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: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
---
drivers/net/can/pch_can.c | 31 ++++++++++++-------------------
1 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index a9b6a65..f0f1404 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -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 @@ MSG_OBJ:
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++;
}
- 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);
--
1.6.0.6