fix zuart dma receiver bug

components/hardware/uart/zuart_dma_receiver.cpp

@@ -36,6 +36,7 @@ void ZUARTDmaReceiver::periodJOBIrq() {  //
     m_lastrxticket = zos_get_tick();
   }
 
+  if (m_rxlen != 0) {
     if (zos_haspassedms(m_lastrxticket) > m_hw_config.rxovertime_ms) {
       if (m_cb) m_cb(m_rxbuf, m_rxlen);
 
@@ -43,4 +44,11 @@ void ZUARTDmaReceiver::periodJOBIrq() {  //
       HAL_UART_DMAStop(m_hw_config.huart);
       HAL_UART_Receive_DMA(m_hw_config.huart, (uint8_t *)m_rxbuf, m_rxbufsize);
     }
+  } else {
+    // 如果DMA接收停止了，重新启动
+    if (!(HAL_UART_GetState(m_hw_config.huart) & 0x1)) {
+      HAL_UART_DMAStop(m_hw_config.huart);
+      HAL_UART_Receive_DMA(m_hw_config.huart, (uint8_t *)m_rxbuf, m_rxbufsize);
+    }
+  }
 }