Re: [PATCH 09/19] ASoC: amd: ps: add support for Soundwire DMA interrupts

From: Pierre-Louis Bossart
Date: Wed Jan 11 2023 - 11:36:44 EST





> @@ -167,9 +167,11 @@ struct acp63_dev_data {
> struct platform_device *pdev[ACP63_DEVS];
> struct mutex acp_lock; /* protect shared registers */
> struct fwnode_handle *sdw_fw_node;
> + struct work_struct acp_sdw_dma_work;
> u16 pdev_mask;
> u16 pdev_count;
> u16 pdm_dev_index;
> + u16 dma_intr_stat[ACP63_SDW_MAX_STREAMS];

streams and DMAs are different things in SoundWire. You can have a 1:N
mapping.

> u8 sdw_master_count;
> u16 sdw0_dev_index;
> u16 sdw1_dev_index;
> diff --git a/sound/soc/amd/ps/pci-ps.c b/sound/soc/amd/ps/pci-ps.c
> index 0fbe5e27f3fb..5b82ee8e3ad8 100644
> --- a/sound/soc/amd/ps/pci-ps.c
> +++ b/sound/soc/amd/ps/pci-ps.c
> @@ -113,14 +113,37 @@ static int acp63_deinit(void __iomem *acp_base, struct device *dev)
> return 0;
> }
>
> +static void acp63_sdw_dma_workthread(struct work_struct *work)
> +{
> + struct acp63_dev_data *adata = container_of(work, struct acp63_dev_data,
> + acp_sdw_dma_work);
> + struct sdw_dma_dev_data *sdw_dma_data;
> + u32 stream_index;
> + u16 pdev_index;
> +
> + pdev_index = adata->sdw_dma_dev_index;
> + sdw_dma_data = dev_get_drvdata(&adata->pdev[pdev_index]->dev);
> +
> + for (stream_index = 0; stream_index < ACP63_SDW_MAX_STREAMS; stream_index++) {
> + if (adata->dma_intr_stat[stream_index]) {
> + if (sdw_dma_data->sdw_stream[stream_index])
> + snd_pcm_period_elapsed(sdw_dma_data->sdw_stream[stream_index]);

is there a reason why you do this in a work thread?

IIRC we did this in SOF because of an issue where during an xrun a stop
IPC would be sent while we were dealing with an IPC.

I don't quite see why it's needed for a DMA?

What am I missing?

> + adata->dma_intr_stat[stream_index] = 0;
> + }
> + }
> +}