usbnet: Fix tx_packets stat for FLAG_MULTI_FRAME drivers

Currently the usbnet core does not update the tx_packets statistic for
drivers with FLAG_MULTI_PACKET and there is no hook in the TX
completion path where they could do this.

cdc_ncm and dependent drivers are bumping tx_packets stat on the
transmit path while asix and sr9800 aren't updating it at all.

Add a packet count in struct skb_data so these drivers can fill it
in, initialise it to 1 for other drivers, and add the packet count
to the tx_packets statistic on completion.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Tested-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index d9a4905e01d0..ff3fb2bd0e90 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -228,8 +228,20 @@ struct skb_data {	/* skb->cb is one of these */
         struct usbnet           *dev;
         enum skb_state          state;
         size_t                  length;
+        unsigned long           packets;
 };
 
+/* Drivers that set FLAG_MULTI_PACKET must call this in their
+ * tx_fixup method before returning an skb.
+ */
+static inline void
+usbnet_set_skb_tx_stats(struct sk_buff *skb, unsigned long packets)
+{
+        struct skb_data *entry = (struct skb_data *) skb->cb;
+
+        entry->packets = packets;
+}
+
 extern int usbnet_open(struct net_device *net);
 extern int usbnet_stop(struct net_device *net);
 extern netdev_tx_t usbnet_start_xmit(struct sk_buff *skb,