使用307的I2S3连接CS43L22播放SD卡中的WAV出现杂音是为什么？

使用307的I2S3连接CS43L22播放SD卡中的WAV，能正常3秒左右，后面就是杂音了。用调试器跟踪SD读取数据是正确的，现在找不到原因，


static void i2s3_init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure={0};


    RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC, ENABLE);


    GPIO_PinRemapConfig( GPIO_Remap_SWJ_JTAGDisable, ENABLE );


    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);


    GPIO_InitStructure.GPIO_Pin =GPIO_Pin_3 | GPIO_Pin_5;
    GPIO_Init(GPIOB, &GPIO_InitStructure);


    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
    GPIO_Init(GPIOC, &GPIO_InitStructure);
}
void i2s_open(uint16_t *audio_buffer, uint16_t buffer_size,
        uint32_t sample_rate, uint32_t frame_format) {
    I2S_InitTypeDef I2S_InitStructure = { 0 };
    DMA_InitTypeDef DMA_InitStructure = { 0 };
    NVIC_InitTypeDef NVIC_InitStructure={0};


    RCC_AHBPeriphClockCmd( RCC_AHBPeriph_DMA2, ENABLE);


    NVIC_InitStructure.NVIC_IRQChannel = DMA2_Channel2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);


    DMA_DeInit(DMA2_Channel2);


    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) &SPI3->DATAR;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) audio_buffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = buffer_size;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA2_Channel2, &DMA_InitStructure);


    DMA_ITConfig(DMA2_Channel2, DMA_IT_TC | DMA_IT_HT, ENABLE);
    DMA_ClearFlag(DMA2_FLAG_TC2 | DMA2_FLAG_HT2);


    I2S_InitStructure.I2S_Mode = I2S_Mode_MasterTx;
    I2S_InitStructure.I2S_Standard = I2S_Standard_Phillips;
    I2S_InitStructure.I2S_DataFormat = frame_format;
    I2S_InitStructure.I2S_MCLKOutput = I2S_MCLKOutput_Enable;
    I2S_InitStructure.I2S_AudioFreq = sample_rate;
    I2S_InitStructure.I2S_CPOL = I2S_CPOL_High;
    I2S_Init(SPI3, &I2S_InitStructure);


    /* SPI DMA enable */
    SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, ENABLE);
    I2S_Cmd(SPI3, ENABLE);


    DMA_Cmd(DMA2_Channel2, ENABLE);
}
void DMA2_Channel2_IRQHandler(void) {
    if (DMA_GetITStatus(DMA2_FLAG_TC2)) {
        DMA_ClearFlag(DMA2_FLAG_TC2);
        free_buffer = 1;
        read_flag = 1;
    }


    if (DMA_GetITStatus(DMA2_FLAG_HT2)) {
        DMA_ClearFlag(DMA2_FLAG_HT2);
        free_buffer = 0;
        read_flag = 1;
    }
}