samsung_sm8750/android_kernel_samsung_sm8750
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

usbnet: Fix tx_bytes statistic running backward in cdc_ncm

Browse Source 
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: beeecd42c3 ("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>
This commit is contained in:
Ben Hutchings
2015-03-25 21:41:33 +01:00
committed by David S. Miller
parent 1e9e39f4a2
commit 7a1e890e21
5 changed files with 22 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/usb/usbnet.h
View File

@@ -227,7 +227,7 @@ struct skb_data { /* skb->cb is one of these */
struct urb *urb;
struct usbnet *dev;
enum skb_state state;
size_t length;
long length;
unsigned long packets;
};
@@ -235,11 +235,13 @@ struct skb_data { /* skb->cb is one of these */
* tx_fixup method before returning an skb.
*/
static inline void
usbnet_set_skb_tx_stats(struct sk_buff *skb, unsigned long packets)
usbnet_set_skb_tx_stats(struct sk_buff *skb,
unsigned long packets, long bytes_delta)
{
struct skb_data *entry = (struct skb_data *) skb->cb;
entry->packets = packets;
entry->length = bytes_delta;
}
extern int usbnet_open(struct net_device *net);