On 02/06/2018 01:02 PM, Heiko Schocher wrote:
> Current ifi driver reads first Rx messages, than loopback
> the Tx message, if the IFI_CANFD_INTERRUPT_TXFIFO_REMOVE
> bit is set. This can lead into the case, that Rx messages
> overhelm Tx messages!
>
> Fixed this in the following way:
>
> Set in the IFI_CANFD_TXFIFO_DLC register the FN value to
> 1, so the IFI block loopsback itself the Tx message when
> sended correctly on the canfd bus. Only the IFI block can
> insert the Tx message in the correct place.
>
> The linux driver now needs only to free the skb, when
> the Tx message was sended correctly.
>
> Signed-off-by: Heiko Schocher <h...@denx.de>
> ---
>
> drivers/net/can/ifi_canfd/ifi_canfd.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c
> b/drivers/net/can/ifi_canfd/ifi_canfd.c
> index 05feb8177936..0d36cb8659ae 100644
> --- a/drivers/net/can/ifi_canfd/ifi_canfd.c
> +++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
> @@ -211,6 +211,7 @@ struct ifi_canfd_priv {
> struct napi_struct napi;
> struct net_device *ndev;
> void __iomem *base;
> + unsigned int tx_len;
> };
>
> static void ifi_canfd_irq_enable(struct net_device *ndev, bool enable)
> @@ -617,8 +618,10 @@ static irqreturn_t ifi_canfd_isr(int irq, void *dev_id)
>
> /* TX IRQ */
> if (isr & IFI_CANFD_INTERRUPT_TXFIFO_REMOVE) {
> - stats->tx_bytes += can_get_echo_skb(ndev, 0);
> + can_free_echo_skb(ndev, 0);
> + stats->tx_bytes += priv->tx_len;
> stats->tx_packets++;
> + priv->tx_len = 0;
> can_led_event(ndev, CAN_LED_EVENT_TX);
> }
>
> @@ -889,6 +892,7 @@ static netdev_tx_t ifi_canfd_start_xmit(struct sk_buff
> *skb,
> }
>
> txdlc = can_len2dlc(cf->len);
> + priv->tx_len = txdlc;
> if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) && can_is_canfd_skb(skb)) {
> txdlc |= IFI_CANFD_TXFIFO_DLC_EDL;
> if (cf->flags & CANFD_BRS)
> @@ -898,6 +902,12 @@ static netdev_tx_t ifi_canfd_start_xmit(struct sk_buff
> *skb,
> if (cf->can_id & CAN_RTR_FLAG)
> txdlc |= IFI_CANFD_TXFIFO_DLC_RTR;
>
> + /*
> + * set FNR to 1, so we get our Tx Message looped back
> + * into RxFIFO
> + */
Nit, you can make this into a single-line comment ;-)
Otherwise,
Reviewed-by: Marek Vasut <ma...@denx.de>
> + txdlc += (1 << IFI_CANFD_TXFIFO_DLC_FNR_OFFSET);
> +
> /* message ram configuration */
> writel(txid, priv->base + IFI_CANFD_TXFIFO_ID);
> writel(txdlc, priv->base + IFI_CANFD_TXFIFO_DLC);
>
--
Best regards,
Marek Vasut
