RT-Thread-这个是spi驱动的bug吧？RT-Thread问答社区

这个是spi驱动的bug吧？

发布于 2025-04-21 20:34:34 浏览：52 订阅该版

在lts-4.1.x分支中gd32450z-eval的bsp中，在文件drv_spi.c中267-295行中代码如下

```c
`static struct rt_spi_bus spi_bus[];`

static const struct gd32f4_spi spis[] = {
#ifdef RT_USING_SPI0
    {SPI0, RCU_SPI0, &spi_bus[0]},
#endif

#ifdef RT_USING_SPI1
    {SPI1, RCU_SPI1, &spi_bus[1]},
#endif

#ifdef RT_USING_SPI2
    {SPI2, RCU_SPI2, &spi_bus[2]},
#endif

#ifdef RT_USING_SPI3
    {SPI3, RCU_SPI3, &spi_bus[3]},
#endif

#ifdef RT_USING_SPI4
    {SPI4, RCU_SPI4, &spi_bus[4]},
#endif

#ifdef RT_USING_SPI5
    {SPI5, RCU_SPI5, &spi_bus[5]},
#endif
};

`static struct rt_spi_bus spi_bus[ARR_LEN(spis)];`
```

**我在运行过程中遇到了两个bug。**

**1. 第一个bug **
spis数组对spi_bus的访问不合理。例如，当只使用spi5时，spis和spi_bus数组长度都应该是1，但是&spi_bus[5]进行了越界访问。
**2. 第二个bug**
开头处的
```c
static struct rt_spi_bus spi_bus[];
```
和结尾处的

```c
static struct rt_spi_bus spi_bus[ARR_LEN(spis)];
```
重复定义了spi_bus，并且所定义的spi_bus数组长度不一致。

这两个bug似乎并不总是会造成问题。例如第一个bug在运行过程中可能只破坏了一些无关紧要的变量，第二个bug一般会被编译器优化掉，如果在第二次定义spi_bus时，添加volatile关键字

```c
volatile static struct rt_spi_bus spi_bus[ARR_LEN(spis)];
```
在RT-thread studio中，出现了如下的报错

```c
make -j16 all 
arm-none-eabi-gcc "../drivers/drv_spi.c"
../drivers/drv_spi.c:299:35: error: conflicting types for 'spi_bus'
  299 | volatile static struct rt_spi_bus spi_bus[ARR_LEN(spis)];
      |                                   ^~~~~~~
../drivers/drv_spi.c:271:26: note: previous declaration of 'spi_bus' was here
  271 | static struct rt_spi_bus spi_bus[];
      |                          ^~~~~~~
../drivers/drv_spi.c:271:26: warning: array 'spi_bus' assumed to have one element
make: *** [drivers/subdir.mk:27: drivers/drv_spi.o] Error 1
"make -j16 all" terminated with exit code 2. Build might be incomplete.
```

同时我参考了stm32中一些的bsp，也抛砖引玉，提出我个人的解决方法：
1.定义枚举变量
```c
enum
{
#ifdef BSP_USING_SPI1
    SPI1_INDEX,
#endif
#ifdef BSP_USING_SPI2
    SPI2_INDEX,
#endif
#ifdef BSP_USING_SPI3
    SPI3_INDEX,
#endif
#ifdef BSP_USING_SPI4
    SPI4_INDEX,
#endif
#ifdef BSP_USING_SPI5
    SPI5_INDEX,
#endif
#ifdef BSP_USING_SPI6
    SPI6_INDEX,
#endif
	SPI_NUM
};
```

2.修改前文中有问题的代码段为

```c
static struct rt_spi_bus spi_bus[SPI_NUM];

static const struct gd32f4_spi spis[] = {
#ifdef BSP_USING_SPI0
    {SPI0, RCU_SPI0, &spi_bus[SPI0_INDEX]},
#endif

#ifdef BSP_USING_SPI1
    {SPI1, RCU_SPI1, &spi_bus[SPI1_INDEX]},
#endif

#ifdef BSP_USING_SPI2
    {SPI2, RCU_SPI2, &spi_bus[SPI2_INDEX]},
#endif

#ifdef BSP_USING_SPI3
    {SPI3, RCU_SPI3, &spi_bus[SPI3_INDEX]},
#endif

#ifdef BSP_USING_SPI4
    {SPI4, RCU_SPI4, &spi_bus[SPI4_INDEX]},
#endif

#ifdef BSP_USING_SPI5
    {SPI5, RCU_SPI5, &spi_bus[SPI5_INDEX]},
#endif
};
```