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authorJim Baxter <jim_baxter@mentor.com>2014-07-07 21:33:18 +0400
committerFelipe Balbi <balbi@ti.com>2014-07-10 17:49:38 +0400
commit6d3865f9d41f15ddbcecaa6722871fc0db21d7ab (patch)
tree2f4ed7cce199a98fadc042403d6f0088fff3f0a1 /drivers/usb/gadget/u_ether.c
parent370af734dfaf8336b496b386e194648e097e248a (diff)
downloadlinux-6d3865f9d41f15ddbcecaa6722871fc0db21d7ab.tar.xz
usb: gadget: NCM: Add transmit multi-frame.
This adds multi-frame support to the NCM NTB's for the gadget driver. This allows multiple network packets to be put inside a single USB NTB with a maximum size of 16kB. It has a time out of 300ms to ensure that smaller number of packets still maintain a normal latency. Also the .fp_index and .next_fp_index have been changed to .ndp_index and .next_ndp_index to match the latest CDC-NCM specification and help with maintenance. Results transmitting from gadget to host. Before the change: TCP_STREAM Throughput (10^6bits/sec): 22.72 UDP_STREAM Throughput (10^6bits/sec): 25.94 Latency: netperf -H 192.168.1.101 -v2 -l 50 -t TCP_RR -- -r 16384,16384 Trans. RoundTrip Throughput Rate Latency 10^6bits/s per sec usec/Tran Outbound 100.83 9918.116 13.215 After the change: TCP_STREAM Throughput (10^6bits/sec): 124.26 UDP_STREAM Throughput (10^6bits/sec): 227.48 Latency: netperf -H 192.168.1.101 -v2 -l 50 -t TCP_RR -- -r 16384,16384 Trans. RoundTrip Throughput Rate Latency 10^6bits/s per sec usec/Tran Outbound 156.80 6377.730 20.552 Signed-off-by: Jim Baxter <jim_baxter@mentor.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb/gadget/u_ether.c')
-rw-r--r--drivers/usb/gadget/u_ether.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c
index 3d78a8844e43..6e6f87656e7b 100644
--- a/drivers/usb/gadget/u_ether.c
+++ b/drivers/usb/gadget/u_ether.c
@@ -483,7 +483,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
struct net_device *net)
{
struct eth_dev *dev = netdev_priv(net);
- int length = skb->len;
+ int length = 0;
int retval;
struct usb_request *req = NULL;
unsigned long flags;
@@ -500,13 +500,13 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
}
spin_unlock_irqrestore(&dev->lock, flags);
- if (!in) {
+ if (skb && !in) {
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
/* apply outgoing CDC or RNDIS filters */
- if (!is_promisc(cdc_filter)) {
+ if (skb && !is_promisc(cdc_filter)) {
u8 *dest = skb->data;
if (is_multicast_ether_addr(dest)) {
@@ -557,11 +557,17 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
if (dev->port_usb)
skb = dev->wrap(dev->port_usb, skb);
spin_unlock_irqrestore(&dev->lock, flags);
- if (!skb)
+ if (!skb) {
+ /* Multi frame CDC protocols may store the frame for
+ * later which is not a dropped frame.
+ */
+ if (dev->port_usb->supports_multi_frame)
+ goto multiframe;
goto drop;
-
- length = skb->len;
+ }
}
+
+ length = skb->len;
req->buf = skb->data;
req->context = skb;
req->complete = tx_complete;
@@ -604,6 +610,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
dev_kfree_skb_any(skb);
drop:
dev->net->stats.tx_dropped++;
+multiframe:
spin_lock_irqsave(&dev->req_lock, flags);
if (list_empty(&dev->tx_reqs))
netif_start_queue(net);