On 02.07.2022 15:01:27, Biju Das wrote:
> Chapter 6.5.16 of the RZ/N1 Peripheral Manual mentions the below
> differences compared to the reference Philips SJA1000 device.
>
> Handling of Transmitted Messages:
> * The CAN controller does not copy transmitted messages to the receive
> buffer, unlike the reference device.
This is something different than....
> int register_sja1000dev(struct net_device *dev)
> {
> + struct sja1000_priv *priv = netdev_priv(dev);
> int ret;
>
> if (!sja1000_probe_chip(dev))
> return -ENODEV;
>
> - dev->flags |= IFF_ECHO; /* we support local echo */
> + if (!(priv->flags & SJA1000_NO_HW_LOOPBACK_QUIRK))
> + dev->flags |= IFF_ECHO; /* we support local echo */
... the IFF_ECHO.
IFF_ECHO set means the driver cals can_put_echo_skb() before TX and
can_get_echo_skb() after TX complete interrupt.
| irqreturn_t sja1000_interrupt(int irq, void *dev_id)
[...]
| while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
| (n < SJA1000_MAX_IRQ)) {
|
| status = priv->read_reg(priv, SJA1000_SR);
| /* check for absent controller due to hw unplug */
| if (status == 0xFF && sja1000_is_absent(priv))
| goto out;
|
| if (isrc & IRQ_WUI)
| netdev_warn(dev, "wakeup interrupt\n");
|
| if (isrc & IRQ_TI) {
| /* transmission buffer released */
| if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
| !(status & SR_TCS)) {
| stats->tx_errors++;
| can_free_echo_skb(dev, 0, NULL);
| } else {
Please add a netdev_info() for debugging and verify that you get a TX
complete IRQ.
| /* transmission complete */
| stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
| stats->tx_packets++;
| }
| netif_wake_queue(dev);
| }
If your hardware doesn't support hardware loopback (configured via
CMD_SRR):
| if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
| cmd_reg_val |= CMD_SRR;
| else
| cmd_reg_val |= CMD_TR;
then don't set CAN_CTRLMODE_LOOPBACK in priv->can.ctrlmode_supported.
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
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