RT-Thread DMA串口接收数据问题

479714284

/*
* Copyright (c) 2006-2023, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date           Author       Notes
* 2023-05-30     RT-Thread    first version
*/

#include <rtthread.h>

#define FINSH_USING_SYMTAB
#define DBG_TAG "main"
#define DBG_LVL DBG_LOG
#include <rtdbg.h>
#include <serial.h>


rt_device_t u1_dev;

struct rt_semaphore sem;

rt_thread_t u1_th;

rt_size_t rx_len = 0;

struct serial_configure u1_configs=RT_SERIAL_CONFIG_DEFAULT;

rt_err_t rx_callback(rt_device_t dev, rt_size_t size)
{
    rx_len=size;
    rt_sem_release(&sem);
    return RT_EOK;

}

void serial_thread_entry(void *parameter){
    rt_size_t len=0;
    char buffer[512]={0};
    while(1){
    rt_sem_take(&sem, RT_WAITING_FOREVER);
    len=rt_device_read(u1_dev, 0, buffer, rx_len);
    buffer[len]='\0';
    rt_kprintf("buffer:");
    rt_kprintf("buffer:%s\n",buffer);
    }
}
int main(void)
{
    rt_err_t ret=0;
    u1_dev=rt_device_find("uart1");
    if(u1_dev==RT_NULL)
    {
        LOG_E("rt_device_find(uart1) failed...\n");
        return -EINVAL;
    }

    ret=rt_device_open(u1_dev, RT_DEVICE_FLAG_DMA_RX);
    if(ret<0)
    {
        LOG_E("rt_device_open(uart1) failed...\n");
        rt_kprintf("ret:%d\n",ret);
        return ret;
    }
    rt_device_control(u1_dev, RT_DEVICE_CTRL_CONFIG, (void *)&u1_configs);
    rt_device_set_rx_indicate(u1_dev, rx_callback);

    ret=rt_sem_init(&sem, "rx_sem", 0, RT_IPC_FLAG_FIFO);
    if(ret<0)
        {
            LOG_E("rt_device_init(%d) failed...\n",ret);
            return ret;
        }

    u1_th=rt_thread_create("u1_recv", serial_thread_entry, NULL, 1024, 10, 5);
    rt_thread_startup(u1_th);
    rt_device_write(u1_dev, 0, "Uart1 config ...\n", rt_strlen("Uart1 config ...\n"));


    return RT_EOK;
}
无法打印出“buffer：加数据”