STM32F207ZE UART2 DMA 接收存在问题

发布于 2021-11-03 10:56:55 浏览：1010 订阅该版

RT-Thread Studio  版本: 2.1.2
RT-Thread 4.0.3

按照https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/device/uart/uart_v1/uart 文档中描述的，使用uart2 dma 接收数据，但是每次调用rt_device_open会出现错误
```
psr: 0x01000000
r00: 0x2000121c
r01: 0x00000200
r02: 0x0800f210
r03: 0x12ab9cba
r04: 0xdeadbeef
r05: 0xdeadbeef
r06: 0xdeadbeef
r07: 0x20002fd0
r08: 0xdeadbeef
r09: 0xdeadbeef
r10: 0xdeadbeef
r11: 0xdeadbeef
r12: 0x00000000
 lr: 0x08008ab9
 pc: 0x08008f7c
hard fault on thread: tshell

thread   pri  status      sp     stack size max used left tick  error
-------- ---  ------- ---------- ----------  ------  ---------- ---
tshell    20  running 0x000000c8 0x00001000    10%   0x00000008 000
tidle0    31  ready   0x00000070 0x00000100    43%   0x00000009 000
timer      4  suspend 0x0000007c 0x00000200    24%   0x00000009 000
main      10  suspend 0x000000bc 0x00000800    14%   0x00000013 000
bus fault:
SCB_CFSR_BFSR:0x82 PRECISERR SCB->BFAR:12AB9CBA
```
原因是调用DMA_CalcBaseAndBitshift的时候hdma->Instance为空导致的

代码如下
```c
#include <rtthread.h>

static char hello[] = "hello rtthread!\n";
#define SAMPLE_UART_NAME       "uart2"

static rt_device_t serial_port = RT_NULL;
static struct rt_messagequeue rx_mq;

struct rx_msg
{
    rt_device_t dev;
    rt_size_t size;
};

static void serial_thread_entry(void* parameter)
{
    struct rx_msg msg;
    rt_err_t result;
    rt_uint32_t rx_length;
    static char rx_buffer[RT_SERIAL_RB_BUFSZ + 1];

while(1)
    {
        rt_memset(&msg, 0, sizeof(msg));
        result = rt_mq_recv(&rx_mq, &msg, sizeof(msg), 0);
        if(RT_EOK == result)
        {
            rx_length = rt_device_read(msg.dev, 0, rx_buffer, msg.size);
            rx_buffer[rx_length] = '\0';
            /* 打印数据 */
            //rt_kprintf("%s\n",rx_buffer);
        }
    }
}

static rt_err_t uart_input(rt_device_t dev, rt_size_t size)
{
    struct rx_msg msg;
    rt_err_t result = RT_EOK;
    msg.dev = dev;
    msg.size = size;

result = rt_mq_send(&rx_mq, &msg, sizeof(msg));
    if(result == -RT_EFULL)
    {
        //rt_kprintf("message queue full!\n");
    }
    return result;
}

static int dma_uart_sample(void)
{
    rt_err_t result = RT_EOK;
    static char msg_pool[256];

serial_port = rt_device_find(SAMPLE_UART_NAME);
    if(serial_port == RT_NULL){
        rt_kprintf("find %s failed!\n", SAMPLE_UART_NAME);
        return RT_ERROR;
    }

/* 初始化消息队列 */
    rt_mq_init(&rx_mq, "rx_mq", msg_pool,
            sizeof(struct rx_msg), sizeof(msg_pool), RT_IPC_FLAG_FIFO);

rt_device_set_rx_indicate(serial_port, uart_input);
    result = rt_device_open(serial_port, RT_DEVICE_FLAG_DMA_RX);
    if(RT_EOK != result)return result;

rt_thread_t thread = rt_thread_create("serial", serial_thread_entry,
            RT_NULL, 1024, 25, 10);
    if(RT_NULL == thread)
    {
        result = RT_ERROR;
    }
    else
    {
        rt_thread_startup(thread);
    }
    return result;
}

/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(dma_uart_sample, uart device dma sample);
```

board.h中配置如下
```c
#define BSP_UART2_RX_USING_DMA
//#define BSP_UART2_TX_USING_DMA

#define BSP_USING_UART1
#define BSP_UART1_TX_PIN       "PA9"
#define BSP_UART1_RX_PIN       "PA10"

#define BSP_USING_UART2
#define BSP_UART2_TX_PIN       "PA2"
#define BSP_UART2_RX_PIN       "PA3"
```
rtconfig.h中也已经打开了 使用uart dma功能

请帮忙分析问题出现在哪里，谢谢