硬件定时器超时为什么会影响串口接收回调呢

串口DMA方式接收，在接收回调里打开硬件定时器

int hwtimer_sample(void)
{
rt_err_t ret = RT_EOK;
rt_hwtimerval_t timeout_s; /* 定时器超时值 /
rt_hwtimer_mode_t mode; / 定时器模式 /
rt_uint32_t freq = 10000; / 计数频率 /
/ 查找定时器设备 /
hw_dev = rt_device_find(HWTIMER_DEV_NAME);
if (hw_dev == RT_NULL)
{
rt_kprintf("hwtimer sample run failed! can't find %s device!\n", HWTIMER_DEV_NAME);
return RT_ERROR;
}
/ 以读写方式打开设备 /
ret = rt_device_open(hw_dev, RT_DEVICE_OFLAG_RDWR);
if (ret != RT_EOK)
{
rt_kprintf("open %s device failed!\n", HWTIMER_DEV_NAME);
return ret;
}
/ 设置超时回调函数 /
rt_device_set_rx_indicate(hw_dev, timeout_cb);
/ 设置计数频率(若未设置该项，默认为1Mhz 或 支持的最小计数频率) /
rt_device_control(hw_dev, HWTIMER_CTRL_FREQ_SET, &freq);
/ 设置模式为周期性定时器（若未设置，默认是HWTIMER_MODE_ONESHOT）*/
mode = HWTIMER_MODE_ONESHOT;
ret = rt_device_control(hw_dev, HWTIMER_CTRL_MODE_SET, &mode);
if (ret != RT_EOK)
{
rt_kprintf("set mode failed! ret is :%d\n", ret);
return ret;
}
return ret;｝
定时器超时回调

/* 定时器超时回调函数 */
static rt_err_t timeout_cb(rt_device_t dev, rt_size_t size)
{
// rt_kprintf("this is hwtimer timeout callback fucntion!\n");
rt_kprintf("tick is :%d !\n", rt_tick_get());
rt_uint32_t len = 0;
timeout = 1;
len = rt_device_read(dev, 0, USART3_RX_BUF, USART3_RX_LEN);
dump_hex(USART3_RX_BUF, len);
rt_sem_release(&recv_comp);
// if (rx9_length > 0)
// {
// rt_kprintf("rx9_length = %d \n", rx9_length);
// }
return 0;
}
串口接收回调

rt_err_t env_recv_ind(rt_device_t dev, rt_size_t size)
{
rt_hwtimerval_t timeout_s; /* 定时器超时值 /
timeout_s.sec = 0; / 秒 /
timeout_s.usec = 999000; / 微秒 100ms的时候是正常的，但是DTU数据间隔大，改成这个试试 DTU用延时做了*/
USART3_RX_LEN += size;
rt_kprintf("receive time is %d size == %d\n", rt_tick_get(), size);
// rt_device_write(hw_dev, 0, &timeout_s, sizeof(timeout_s)) ;
/* release semaphore to let finsh thread rx data */
// if (size > 0)
// rt_sem_release(&env_rx);
return RT_EOK;
}
现象：加上开启定时器的时候，如下，相当于卡了1s，没接收新的数据

去掉开启定时器的时候，如下，一直能接收到

这个开启定时器还影响串口接收吗？

我之前也用到了这两个，可以正常，现在是想优化一下，谢谢