10 关于littlefs中，读取文件数据错误

发布于 2021-10-29 13:42:18 浏览：1475 订阅该版

```c
#include <sfud.h>
#include <stdarg.h>
#include "main.h"

#define	W25QXX_CS_SET 		HAL_GPIO_WritePin(SPI1_CS_GPIO_Port,SPI1_CS_Pin,GPIO_PIN_SET);  		//W25QXXµÄÆ¬Ñ¡ÐÅºÅ²»Ñ¡Í¨
#define	W25QXX_CS_RESET 		HAL_GPIO_WritePin(SPI1_CS_GPIO_Port,SPI1_CS_Pin,GPIO_PIN_RESET);  		//W25QXXµÄÆ¬Ñ¡ÐÅºÅ²»Ñ¡Í¨

osMutexId SPIMutexHandle;
static char log_buf[256];

void sfud_log_debug(const char *file, const long line, const char *format, ...);

/**
 * SPI write data then read data
 */
static sfud_err spi_write_read(const sfud_spi *spi,uint8_t *write_buf, size_t write_size, uint8_t *read_buf, size_t read_size) 
{
    sfud_err result = SFUD_SUCCESS;

if (write_size)
        SFUD_ASSERT(write_buf);

if (read_size)
        SFUD_ASSERT(read_buf);

/* µÍµçÆ½ÐÅºÅÊ¹ÄÜCSÒý½Å */
    W25QXX_CS_RESET;
    /* ¿ªÊ¼¶ÁÐ´Êý¾Ý */
		if(read_size && write_size)
		{
			if( HAL_OK != HAL_SPI_Transmit(&hspi1, (uint8_t *)write_buf, write_size, 1000) )
				result = SFUD_ERR_TIMEOUT;
			if( HAL_OK != HAL_SPI_Receive(&hspi1, (uint8_t *)read_buf, read_size, 1000) )
				result = SFUD_ERR_TIMEOUT;
		}
		else if (write_size)
		{
			if( HAL_OK != HAL_SPI_Transmit(&hspi1, (uint8_t *)write_buf, write_size, 1000) )
				result = SFUD_ERR_TIMEOUT;
		}
		else
		{
			if( HAL_OK != HAL_SPI_Receive(&hspi1, (uint8_t *)read_buf, read_size, 1000) )
				result = SFUD_ERR_TIMEOUT;
		}
		/* ¸ßµçÆ½ÐÅºÅÊ§ÄÜCSÒý½Å */
    W25QXX_CS_SET;

return result;
}

static void spi_lock(const sfud_spi *spi) {
	osMutexWait(SPIMutexHandle, portMAX_DELAY);
}

static void spi_unlock(const sfud_spi *spi) {
	osMutexRelease(SPIMutexHandle); 
}

/* about 100 microsecond delay */
static void retry_delay_100us(void) {
    DWT_Delay_us(100);
}

sfud_err sfud_spi_port_init(sfud_flash *flash) 
{
    sfud_err result = SFUD_SUCCESS;
    
	  osMutexDef(spiMutex);
		SPIMutexHandle = osMutexCreate(osMutex(spiMutex));
	  
		/* Í¬²½ Flash ÒÆÖ²ËùÐèµÄ½Ó¿Ú¼°Êý¾Ý */
		flash->spi.wr = spi_write_read;
		flash->spi.lock = spi_lock;
		flash->spi.unlock = spi_unlock;

/* about 100 microsecond delay */
		flash->retry.delay = retry_delay_100us;
		/* adout 60 seconds timeout */
		flash->retry.times = 60 * 10000;

return result;
}

/**
 * This function is print debug info.
 *
 * @param file the file which has call this function
 * @param line the line number which has call this function
 * @param format output format
 * @param ... args
 */
void sfud_log_debug(const char *file, const long line, const char *format, ...) {
    va_list args;

/* args point to the first variable parameter */
    va_start(args, format);
    printf("[SFUD](%s:%ld) ", file, line);
    /* must use vprintf to print */
    vsnprintf(log_buf, sizeof(log_buf), format, args);
    printf("%s\r\n", log_buf);
    va_end(args);
}

/**
 * This function is print routine info.
 *
 * @param format output format
 * @param ... args
 */
void sfud_log_info(const char *format, ...) {
    va_list args;

/* args point to the first variable parameter */
    va_start(args, format);
    printf("[SFUD]");
    /* must use vprintf to print */
    vsnprintf(log_buf, sizeof(log_buf), format, args);
    printf("%s\r\n", log_buf);
    va_end(args);
}
```
之前在RTT里使用没有任何问题，现在换了FREERTOS,将littlefs移植过来之后，写文件没有出现过问题，但是读文件时会出现文件命名还有数据，读出来的数据长度是0，或者读出的数据出现很多0xff，此时retry_time之后，查询spi总线状态，发现一直处于busy。