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Message-ID: <0d2ccd69-63e3-b8c5-396b-b698110cad14@linux.intel.com>
Date:   Wed, 11 Jan 2023 09:38:30 -0600
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Subject: Re: [PATCH 09/19] ASoC: amd: ps: add support for Soundwire DMA
 interrupts
Content-Language: en-US
To:     Vijendar Mukunda <Vijendar.Mukunda@amd.com>, broonie@kernel.org,
        vkoul@kernel.org, alsa-devel@alsa-project.org
Cc:     Basavaraj.Hiregoudar@amd.com, Sunil-kumar.Dommati@amd.com,
        Mario.Limonciello@amd.com, Mastan.Katragadda@amd.com,
        arungopal.kondaveeti@amd.com, Liam Girdwood <lgirdwood@gmail.com>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Syed Saba Kareem <Syed.SabaKareem@amd.com>,
        Nathan Chancellor <nathan@kernel.org>,
        open list <linux-kernel@vger.kernel.org>
References: <20230111090222.2016499-1-Vijendar.Mukunda@amd.com>
 <20230111090222.2016499-10-Vijendar.Mukunda@amd.com>
From:   Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
In-Reply-To: <20230111090222.2016499-10-Vijendar.Mukunda@amd.com>
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> @@ -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;
> +		}
> +	}
> +}