On 12.02.2025 10:49:43, Ming Yu wrote:
> > > +static void nct6694_can_handle_state_errors(struct net_device *ndev, u8 status)
> > > +{
> > > + struct nct6694_can_priv *priv = netdev_priv(ndev);
> >
> > It seems you don't have dedicated RX and TX states, so call
> > nct6694_can_get_berr_counter() and use can_state_get_by_berr_counter()
> > to get the states. Then basically do that what what
> > mcp251xfd_handle_cerrif() does, starting with "new_state = max(tx_state, rx_state);"
> >
>
> Excuse me, do you mean that nct6694_can_handle_state_change() the flow
> should like v5?
> https://lore.kernel.org/linux-can/CAMZ6RqLHEoukxDfV33iDWXjM1baK922QnWSkOP01VzZ0S_9H8g@xxxxxxxxxxxxxx/
The handling of
CAMZ6RqLHEoukxDfV33iDWXjM1baK922QnWSkOP01VzZ0S_9H8g@xxxxxxxxxxxxxx in v5
was better, but there were some questions by Vincent...
So let's continue the discussion from v5 here:
> > +static void nct6694_can_handle_state_change(struct net_device *ndev,
> > + u8 status)
> > +{
> > + struct nct6694_can_priv *priv = netdev_priv(ndev);
> > + enum can_state new_state = priv->can.state;
> > + enum can_state rx_state, tx_state;
> > + struct can_berr_counter bec;
> > + struct can_frame *cf;
> > + struct sk_buff *skb;
> > +
> > + nct6694_can_get_berr_counter(ndev, &bec);
> > + can_state_get_by_berr_counter(ndev, &bec, &tx_state, &rx_state);
>
> Here, you set up tx_state and rx_state...
>
remove the switch (status)...
> > + switch (status) {
> > + case NCT6694_CAN_EVT_STS_ERROR_ACTIVE:
> > + new_state = CAN_STATE_ERROR_ACTIVE;
> > + break;
> > + case NCT6694_CAN_EVT_STS_ERROR_PASSIVE:
> > + new_state = CAN_STATE_ERROR_PASSIVE;
> > + break;
> > + case NCT6694_CAN_EVT_STS_BUS_OFF:
> > + new_state = CAN_STATE_BUS_OFF;
> > + break;
> > + case NCT6694_CAN_EVT_STS_WARNING:
> > + new_state = CAN_STATE_ERROR_WARNING;
> > + break;
> > + default:
> > + netdev_err(ndev, "Receive unknown CAN status event.\n");
> > + return;
> > + }
replace it by:
new_state = max(tx_state, rx_state);
> > +
> > + /* state hasn't changed */
> > + if (new_state == priv->can.state)
> > + return;
> > +
> > + skb = alloc_can_err_skb(ndev, &cf);
> > +
remove this VVV
> > + tx_state = bec.txerr >= bec.rxerr ? new_state : 0;
> > + rx_state = bec.txerr <= bec.rxerr ? new_state : 0;
^^^
>
> ... but you never used the values returned by
> can_state_get_by_berr_counter() and just overwrote the tx and rx
> state.
>
> What is the logic here? Why do you need to manually adjust those two
> values? Isn't the logic in can_change_state() sufficient?
>
> > + can_change_state(ndev, cf, tx_state, rx_state);
> > +
> > + if (new_state == CAN_STATE_BUS_OFF) {
if (priv->can.state == CAN_STATE_BUS_OFF) {
>
> Same for the new_state. The function can_change_state() calculate the
> new state from tx_state and rx_state and save it under
> can_priv->state. But here, you do your own calculation.
>
> Only keep one of the two. If your device already tells you the state,
> then fine! Just use the information from your device and do not use
> can_change_state(). Here, you are doing double work resulting in a
> weird mix.
>
what does your device do when it goes into bus off?
> > + can_bus_off(ndev);
> > + } else if (skb) {
> > + cf->can_id |= CAN_ERR_CNT;
> > + cf->data[6] = bec.txerr;
> > + cf->data[7] = bec.rxerr;
> > + }
> > +
if (skb)
> > + nct6694_can_rx_offload(&priv->offload, skb);
> > +}
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
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