can组件驱动中_can_int_tx 调用底层发送msg时 如果有暂时无法恢复的总线错误会卡死

can组件驱动中_can_int_tx 调用底层发送msg时 如果有暂时无法恢复的总线错误会卡死

rt_inline int _can_int_tx(struct rt_can_device *can, const struct rt_can_msg *data, int msgs)
{
int size;
struct rt_can_tx_fifo *tx_fifo;

RT_ASSERT(can != RT_NULL);

size = msgs;
tx_fifo = (struct rt_can_tx_fifo *) can->can_tx;
RT_ASSERT(tx_fifo != RT_NULL);

while (msgs)
{
    rt_base_t level;
    rt_uint32_t no;
    rt_uint32_t result;
    struct rt_can_sndbxinx_list *tx_tosnd = RT_NULL;

    rt_sem_take(&(tx_fifo->sem), RT_WAITING_FOREVER);
    level = rt_hw_interrupt_disable();
    tx_tosnd = rt_list_entry(tx_fifo->freelist.next, struct rt_can_sndbxinx_list, list);
    RT_ASSERT(tx_tosnd != RT_NULL);
    rt_list_remove(&tx_tosnd->list);
    rt_hw_interrupt_enable(level);

    no = ((rt_uint32_t)tx_tosnd - (rt_uint32_t)tx_fifo->buffer) / sizeof(struct rt_can_sndbxinx_list);
    tx_tosnd->result = RT_CAN_SND_RESULT_WAIT;
    **if (can->ops->sendmsg(can, data, no) != RT_EOK)**
    {
        /* send failed. */
        level = rt_hw_interrupt_disable();
        rt_list_insert_after(&tx_fifo->freelist, &tx_tosnd->list);
        rt_hw_interrupt_enable(level);
        rt_sem_release(&(tx_fifo->sem));
        **continue;**
    }

    can->status.sndchange = 1;
    rt_completion_wait(&(tx_tosnd->completion), RT_WAITING_FOREVER);

    level = rt_hw_interrupt_disable();
    result = tx_tosnd->result;
    if (!rt_list_isempty(&tx_tosnd->list))
    {
        rt_list_remove(&tx_tosnd->list);
    }
    rt_list_insert_before(&tx_fifo->freelist, &tx_tosnd->list);
    rt_hw_interrupt_enable(level);
    rt_sem_release(&(tx_fifo->sem));

    if (result == RT_CAN_SND_RESULT_OK)
    {
        level = rt_hw_interrupt_disable();
        can->status.sndpkg++;
        rt_hw_interrupt_enable(level);

        data ++;
        msgs -= sizeof(struct rt_can_msg);
        if (!msgs) break;
    }
    else
    {
        level = rt_hw_interrupt_disable();
        can->status.dropedsndpkg++;
        rt_hw_interrupt_enable(level);
        break;
    }
}

return (size - msgs);

}

当总线存在临时物理断开时 调用底层can->ops->sendmsg(can, data, no) 会一直失败 然后再下面分支的continue一直循环

Start at the _can_int_tx function and inspect the can->ops->sendmsg failure branch shown in the issue, along with the CAN driver implementations that return its result. Reproduce the case with a temporarily disconnected CAN bus and trace the retry path; done should mean a persistent send failure no longer leaves transmission stuck in an endless loop.