Gentle Ping!
> From: Pankaj Sharma <pankj.sharma@xxxxxxxxxxx>
> Subject: [PATCH v3] can: m_can: add support for handling arbitration error
>
> The Bosch MCAN hardware (3.1.0 and above) supports interrupt flag to detect
> Protocol error in arbitration phase.
>
> Transmit error statistics is currently not updated from the MCAN driver.
> Protocol error in arbitration phase is a TX error and the network statistics should
> be updated accordingly.
>
> The member "tx_error" of "struct net_device_stats" should be incremented as
> arbitration is a transmit protocol error. Also "arbitration_lost" of "struct
> can_device_stats" should be incremented to report arbitration lost.
>
> Signed-off-by: Pankaj Sharma <pankj.sharma@xxxxxxxxxxx>
> Signed-off-by: Sriram Dash <sriram.dash@xxxxxxxxxxx>
> ---
>
> changes in v3:
> - handle arbitration lost stats even if the allocation of the skb fails
>
> changes in v2:
> - common m_can_ prefix for is_protocol_err function
> - handling stats even if the allocation of the skb fails
> - resolving build errors on net-next branch
>
> drivers/net/can/m_can/m_can.c | 42
> +++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 75e7490c4299..02c5795b7393 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -778,6 +778,43 @@ static inline bool is_lec_err(u32 psr)
> return psr && (psr != LEC_UNUSED);
> }
>
> +static inline bool m_can_is_protocol_err(u32 irqstatus) {
> + return irqstatus & IR_ERR_LEC_31X;
> +}
> +
> +static int m_can_handle_protocol_error(struct net_device *dev, u32
> +irqstatus) {
> + struct net_device_stats *stats = &dev->stats;
> + struct m_can_classdev *cdev = netdev_priv(dev);
> + struct can_frame *cf;
> + struct sk_buff *skb;
> +
> + /* propagate the error condition to the CAN stack */
> + skb = alloc_can_err_skb(dev, &cf);
> +
> + /* update tx error stats since there is protocol error */
> + stats->tx_errors++;
> +
> + /* update arbitration lost status */
> + if (cdev->version >= 31 && (irqstatus & IR_PEA)) {
> + netdev_dbg(dev, "Protocol error in Arbitration fail\n");
> + cdev->can.can_stats.arbitration_lost++;
> + if (skb) {
> + cf->can_id |= CAN_ERR_LOSTARB;
> + cf->data[0] |= CAN_ERR_LOSTARB_UNSPEC;
> + }
> + }
> +
> + if (unlikely(!skb)) {
> + netdev_dbg(dev, "allocation of skb failed\n");
> + return 0;
> + }
> + netif_receive_skb(skb);
> +
> + return 1;
> +}
> +
> static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
> u32 psr)
> {
> @@ -792,6 +829,11 @@ static int m_can_handle_bus_errors(struct net_device
> *dev, u32 irqstatus,
> is_lec_err(psr))
> work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED);
>
> + /* handle protocol errors in arbitration phase */
> + if ((cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
> + m_can_is_protocol_err(irqstatus))
> + work_done += m_can_handle_protocol_error(dev, irqstatus);
> +
> /* other unproccessed error interrupts */
> m_can_handle_other_err(dev, irqstatus);
>
> --
> 2.17.1
