diff options
| author | Ben Hutchings <ben.hutchings@codethink.co.uk> | 2015-03-25 21:41:33 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-29 12:06:45 -0700 |
| commit | 7a1e890e2168e33fb62d84528e996b8b4b478fea (patch) | |
| tree | 2b9d47228b9d613a9934f8bddde26a6633cf748e /drivers/net/usb/usbnet.c | |
| parent | 1e9e39f4a29857a396ac7b669d109f697f66695e (diff) | |
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>
Diffstat (limited to 'drivers/net/usb/usbnet.c')
| -rw-r--r-- | drivers/net/usb/usbnet.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 0f3ff285f6a1..777757ae1973 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1346,9 +1346,19 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, } else urb->transfer_flags |= URB_ZERO_PACKET; } - entry->length = urb->transfer_buffer_length = length; - if (!(info->flags & FLAG_MULTI_PACKET)) - usbnet_set_skb_tx_stats(skb, 1); + urb->transfer_buffer_length = length; + + if (info->flags & FLAG_MULTI_PACKET) { + /* Driver has set number of packets and a length delta. + * Calculate the complete length and ensure that it's + * positive. + */ + entry->length += length; + if (WARN_ON_ONCE(entry->length <= 0)) + entry->length = length; + } else { + usbnet_set_skb_tx_stats(skb, 1, length); + } spin_lock_irqsave(&dev->txq.lock, flags); retval = usb_autopm_get_interface_async(dev->intf); |