Re: [PATCH v3 4/4] can: kvaser_usb: Add support for the Usbcan-II family

On Thu, Jan 08, 2015 at 12:53:37PM +0100, Marc Kleine-Budde wrote:

On 01/05/2015 07:31 PM, Ahmed S. Darwish wrote:

quoted

[...]

quoted

		cf->can_id |= CAN_ERR_CRTL;
		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;

		stats->rx_over_errors++;
		stats->rx_errors++;

		netif_rx(skb);

		stats->rx_packets++;
		stats->rx_bytes += cf->can_dlc;

Another patch would be not to touch cf after netif_rx(), please move the stats handling before calling netif_rx(). Same applies to the kvaser_usb_rx_can_msg() function.

BTW, is it guaranteed from the SocketCAN stack that netif_rx()
will never return NET_RX_DROPPED? Because if no guarantee
exists, I guess below fragment cannot be completely correct?

        stats->rx_packets++;
        stats->rx_bytes += cf->can_dlc;
        netif_rx(skb);

On the other hand, I don't see evan a single CAN driver checking
netif_rx() return value, so maybe such a check is an overkill...

Thanks,
Darwish