[PATCH net v4 2/4] r8152: modify the tx flow

From: Hayes Wang
Date: Mon Nov 18 2013 - 22:26:21 EST


Remove the code for sending the packet in the rtl8152_start_xmit().
Let rtl8152_start_xmit() to queue the packet only, and schedule a
tasklet to send the queued packets. This simplify the code and make
sure all the packet would be sent by the original order.

Signed-off-by: Hayes Wang <hayeswang@xxxxxxxxxxx>
---
drivers/net/usb/r8152.c | 46 +++-------------------------------------------
1 file changed, 3 insertions(+), 43 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 428600d..8a786b6 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1388,53 +1388,13 @@ static netdev_tx_t rtl8152_start_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
struct r8152 *tp = netdev_priv(netdev);
- struct net_device_stats *stats = rtl8152_get_stats(netdev);
- unsigned long flags;
- struct tx_agg *agg = NULL;
- struct tx_desc *tx_desc;
- unsigned int len;
- u8 *tx_data;
- int res;

skb_tx_timestamp(skb);

- /* If tx_queue is not empty, it means at least one previous packt */
- /* is waiting for sending. Don't send current one before it. */
- if (skb_queue_empty(&tp->tx_queue))
- agg = r8152_get_tx_agg(tp);
-
- if (!agg) {
- skb_queue_tail(&tp->tx_queue, skb);
- return NETDEV_TX_OK;
- }
-
- tx_desc = (struct tx_desc *)agg->head;
- tx_data = agg->head + sizeof(*tx_desc);
- agg->skb_num = agg->skb_len = 0;
+ skb_queue_tail(&tp->tx_queue, skb);

- len = skb->len;
- r8152_tx_csum(tp, tx_desc, skb);
- memcpy(tx_data, skb->data, len);
- dev_kfree_skb_any(skb);
- agg->skb_num++;
- agg->skb_len += len;
- usb_fill_bulk_urb(agg->urb, tp->udev, usb_sndbulkpipe(tp->udev, 2),
- agg->head, len + sizeof(*tx_desc),
- (usb_complete_t)write_bulk_callback, agg);
- res = usb_submit_urb(agg->urb, GFP_ATOMIC);
- if (res) {
- /* Can we get/handle EPIPE here? */
- if (res == -ENODEV) {
- netif_device_detach(tp->netdev);
- } else {
- netif_warn(tp, tx_err, netdev,
- "failed tx_urb %d\n", res);
- stats->tx_dropped++;
- spin_lock_irqsave(&tp->tx_lock, flags);
- list_add_tail(&agg->list, &tp->tx_free);
- spin_unlock_irqrestore(&tp->tx_lock, flags);
- }
- }
+ if (!list_empty(&tp->tx_free))
+ tasklet_schedule(&tp->tl);

return NETDEV_TX_OK;
}
--
1.8.3.1

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