記一次CubeMX+STM32+SD+DMA+FATFS文件寫入錯誤的解決

環境：

CubeMX（5.2.1）

HAL庫（1.15.0）

STM32F765IIK（主頻180MHz，關閉Cache）

SDMMC2+DMA

FATFS（R0.12c）

 

測試程序：

void sdcard_test_task(void *p) {
    static FATFS fs;
    FIL fil;
    uint32_t bw;
    const char *w = "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n"
                    "1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234_1234\r\n";

    if (f_mount(&fs, "0:", 1)) {
        __nop();
        return;
    }

    while (1) {
        if (f_open(&fil, "ggg.txt", FA_OPEN_ALWAYS | FA_WRITE) == FR_OK) {
            f_lseek(&fil, f_size(&fil));
            f_write(&fil, w, strlen(w), &bw);
            f_close(&fil);
        } else {
            __nop();
        }

        HAL_Delay(100);
    }
}

問題：

程序運行一段時間後f_open一直返回FR_LOCKED錯誤

 

解決：

重新打開CubeMX，把FATFS的這欄選成Enable即可

其他：

• 這個版本的CubeMX和HAL庫使用SD卡必須打開DMA
• 產生TXUNDERR錯誤：

解決辦法是打開I，DCache

• 別忘了棧可能要調大
• 我在STM32F429I-DISCOVERY這個板子上也試過用CubeMX（5.4.0）生成的代碼（HAL庫V1.24.1）調試SD卡，也遇到了類似的問題。具體是SD卡可以寫但不能讀，讀出錯的原因是SDIO_FLAG_RXOVERR，解決辦法是把HAL_SD_ConfigWideBusOperation(&hsd, SDIO_BUS_WIDE_4B)中的SDIO_BUS_WIDE_4B改成SDIO_BUS_WIDE_1B