usbnet: Fix tx_bytes statistic running backward in cdc_ncm
cdc_ncm disagrees with usbnet about how much framing overhead should
be counted in the tx_bytes statistics, and tries 'fix' this by
decrementing tx_bytes on the transmit path. But statistics must never
be decremented except due to roll-over; this will thoroughly confuse
user-space. Also, tx_bytes is only incremented by usbnet in the
completion path.
Fix this by requiring drivers that set FLAG_MULTI_FRAME to set a
tx_bytes delta along with the tx_packets count.
Fixes: beeecd42c3b4 ("net: cdc_ncm/cdc_mbim: adding NCM protocol statistics")
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c
index 724a9b5..75d6f26 100644
--- a/drivers/net/usb/asix_common.c
+++ b/drivers/net/usb/asix_common.c
@@ -189,7 +189,7 @@
skb_put(skb, sizeof(padbytes));
}
- usbnet_set_skb_tx_stats(skb, 1);
+ usbnet_set_skb_tx_stats(skb, 1, 0);
return skb;
}