diff options
author | Ben Hutchings <ben.hutchings@codethink.co.uk> | 2015-03-25 20:41:33 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2015-03-29 19:06:45 (GMT) |
commit | 7a1e890e2168e33fb62d84528e996b8b4b478fea (patch) | |
tree | 2b9d47228b9d613a9934f8bddde26a6633cf748e /drivers/net | |
parent | 1e9e39f4a29857a396ac7b669d109f697f66695e (diff) | |
download | linux-7a1e890e2168e33fb62d84528e996b8b4b478fea.tar.xz |
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')
-rw-r--r-- | drivers/net/usb/asix_common.c | 2 | ||||
-rw-r--r-- | drivers/net/usb/cdc_ncm.c | 7 | ||||
-rw-r--r-- | drivers/net/usb/sr9800.c | 2 | ||||
-rw-r--r-- | drivers/net/usb/usbnet.c | 16 |
4 files changed, 18 insertions, 9 deletions
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 @@ struct sk_buff *asix_tx_fixup(struct usbnet *dev, struct sk_buff *skb, skb_put(skb, sizeof(padbytes)); } - usbnet_set_skb_tx_stats(skb, 1); + usbnet_set_skb_tx_stats(skb, 1, 0); return skb; } diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 70cbea5..c3e4da9 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -1177,13 +1177,12 @@ cdc_ncm_fill_tx_frame(struct usbnet *dev, struct sk_buff *skb, __le32 sign) ctx->tx_overhead += skb_out->len - ctx->tx_curr_frame_payload; ctx->tx_ntbs++; - /* usbnet has already counted all the framing overhead. + /* usbnet will count all the framing overhead by default. * Adjust the stats so that the tx_bytes counter show real * payload data instead. */ - dev->net->stats.tx_bytes -= skb_out->len - ctx->tx_curr_frame_payload; - - usbnet_set_skb_tx_stats(skb_out, n); + usbnet_set_skb_tx_stats(skb_out, n, + ctx->tx_curr_frame_payload - skb_out->len); return skb_out; diff --git a/drivers/net/usb/sr9800.c b/drivers/net/usb/sr9800.c index 7650cdc..953de13 100644 --- a/drivers/net/usb/sr9800.c +++ b/drivers/net/usb/sr9800.c @@ -144,7 +144,7 @@ static struct sk_buff *sr_tx_fixup(struct usbnet *dev, struct sk_buff *skb, skb_put(skb, sizeof(padbytes)); } - usbnet_set_skb_tx_stats(skb, 1); + usbnet_set_skb_tx_stats(skb, 1, 0); return skb; } diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 0f3ff28..777757a 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); |