[DeviceDriver] Fix can infinite loop when can driver send error

 - in _can_int_tx if can driver sendmsg do not return RT_EOK,
   it will repeat until sendmsg return RT_EOK
 - if error occur on can bus(wire broken or EMI), all threads that
   have lower priority will not be executed
 - we should let application layer to determine if resend is appropriate
   when send fail, besides in data link layer, can already implemented
   auto resend in hardware

1 files changed, 3 insertions, 2 deletions

diff --git a/components/drivers/can/can.c b/components/drivers/can/can.c
index f110bc9e1f..eee78da9ec 100644
--- a/components/drivers/can/can.c
+++ b/components/drivers/can/can.c
@@ -158,10 +158,10 @@ rt_inline int _can_int_tx(struct rt_can_device *can, const struct rt_can_msg *da
         {
             /* send failed. */
             level = rt_hw_interrupt_disable();
-            rt_list_insert_after(&tx_fifo->freelist, &tx_tosnd->list);
+            rt_list_insert_before(&tx_fifo->freelist, &tx_tosnd->list);
             rt_hw_interrupt_enable(level);
             rt_sem_release(&(tx_fifo->sem));
-            continue;
+            goto err_ret;
         }
 
         can->status.sndchange = 1;
@@ -189,6 +189,7 @@ rt_inline int _can_int_tx(struct rt_can_device *can, const struct rt_can_msg *da
         }
         else
         {
+err_ret:
             level = rt_hw_interrupt_disable();
             can->status.dropedsndpkg++;
             rt_hw_interrupt_enable(level);