[alsa-devel] [RESEND PATCH v3 5/6] ASoC: amd: handle ACP3x i2s-sp watermark interrupt.

[Pierre-Louis Bossart]

On 11/7/19 7:24 AM, Ravulapati Vishnu vardhan rao wrote:
> whenever audio data equal to I2S-SP fifo watermark level is
> produced/consumed, interrupt is generated.
> 
> Signed-off-by: Ravulapati Vishnu vardhan rao <Vishnuvardhanrao.Ravulapati at amd.com>
> ---
>   sound/soc/amd/raven/acp3x-pcm-dma.c | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
> 
> diff --git a/sound/soc/amd/raven/acp3x-pcm-dma.c b/sound/soc/amd/raven/acp3x-pcm-dma.c
> index 8fab505..629a32f 100644
> --- a/sound/soc/amd/raven/acp3x-pcm-dma.c
> +++ b/sound/soc/amd/raven/acp3x-pcm-dma.c
> @@ -176,6 +176,13 @@ static irqreturn_t i2s_irq_handler(int irq, void *dev_id)
>   		snd_pcm_period_elapsed(rv_i2s_data->play_stream);
>   		play_flag = 1;
>   	}
> +	if ((val & BIT(I2S_TX_THRESHOLD)) &&
> +				rv_i2s_data->i2ssp_play_stream) {
> +		rv_writel(BIT(I2S_TX_THRESHOLD),
> +			rv_i2s_data->acp3x_base	+ mmACP_EXTERNAL_INTR_STAT);
> +		snd_pcm_period_elapsed(rv_i2s_data->i2ssp_play_stream);

The commit message looks odd. If you have a DMA and signal a period 
elapsed, is this really a case where the FIFO level reaches a watermark?
Usually the FIFOs are somewhat small and there are multiple DMA 
transfers per period?