Messages in this thread | | | Subject | Re: [PATCH v1 1/2] can: do not increase rx statistics when receiving CAN error frames | From | Oliver Hartkopp <> | Date | Tue, 23 Nov 2021 22:01:04 +0100 |
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On 23.11.21 12:53, Vincent Mailhol wrote: > CAN error skb is an interface specific to socket CAN. The CAN error > skb does not correspond to any actual CAN frame sent on the wire. Only > an error flag and a delimiter are transmitted when an error occurs > (c.f. ISO 11898-1 section 10.4.4.2 "Error flag"). > > For this reason, it makes no sense to increment the rx_packets and > rx_bytes fields of struct net_device_stats because no actual payload > were transmitted on the wire. >
(..)
> diff --git a/drivers/net/can/dev/rx-offload.c b/drivers/net/can/dev/rx-offload.c > index 37b0cc65237b..bb47e9a49240 100644 > --- a/drivers/net/can/dev/rx-offload.c > +++ b/drivers/net/can/dev/rx-offload.c > @@ -54,8 +54,10 @@ static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota) > struct can_frame *cf = (struct can_frame *)skb->data; > > work_done++; > - stats->rx_packets++; > - stats->rx_bytes += cf->len; > + if (!(cf->can_id & CAN_ERR_MASK)) {
This looks wrong.
Did you think of CAN_ERR_FLAG ??
> + stats->rx_packets++; > + stats->rx_bytes += cf->len; > + } > netif_receive_skb(skb);
(..)
> diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c > index 1679cbe45ded..d582c39fc8d0 100644 > --- a/drivers/net/can/usb/ucan.c > +++ b/drivers/net/can/usb/ucan.c > @@ -621,8 +621,10 @@ static void ucan_rx_can_msg(struct ucan_priv *up, struct ucan_message_in *m) > memcpy(cf->data, m->msg.can_msg.data, cf->len); > > /* don't count error frames as real packets */ > - stats->rx_packets++; > - stats->rx_bytes += cf->len; > + if (!(cf->can_id & CAN_ERR_FLAG)) {
Ah, here we are :-)
> + stats->rx_packets++; > + stats->rx_bytes += cf->len; > + }
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