Re: [PATCH V6 3/4] ASoC: pcm_dmaengine: Extract snd_dmaengine_pcm_refine_runtime_hwparams

From: John Stultz
Date: Thu Jan 09 2020 - 00:00:33 EST


On Thu, Sep 26, 2019 at 6:50 PM Shengjiu Wang <shengjiu.wang@xxxxxxx> wrote:
>
> When set the runtime hardware parameters, we may need to query
> the capability of DMA to complete the parameters.
>
> This patch is to Extract this operation from
> dmaengine_pcm_set_runtime_hwparams function to a separate function
> snd_dmaengine_pcm_refine_runtime_hwparams, that other components
> which need this feature can call this function.
>
> Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
> Reviewed-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx>

As a heads up, this patch seems to be causing a regression on the HiKey board.

On boot up I'm seeing:
[ 17.721424] hi6210_i2s f7118000.i2s: ASoC: can't open component
f7118000.i2s: -6

And HDMI audio isn't working. With this patch reverted, audio works again.


> diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
> index 89a05926ac73..5749a8a49784 100644
> --- a/sound/core/pcm_dmaengine.c
> +++ b/sound/core/pcm_dmaengine.c
> @@ -369,4 +369,87 @@ int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
...
> + ret = dma_get_slave_caps(chan, &dma_caps);
> + if (ret == 0) {
> + if (dma_caps.cmd_pause && dma_caps.cmd_resume)
> + hw->info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
> + if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
> + hw->info |= SNDRV_PCM_INFO_BATCH;
> +
> + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> + addr_widths = dma_caps.dst_addr_widths;
> + else
> + addr_widths = dma_caps.src_addr_widths;
> + }

It seems a failing ret from dma_get_slave_caps() here is being returned...

> +
> + /*
> + * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
> + * hw.formats set to 0, meaning no restrictions are in place.
> + * In this case it's the responsibility of the DAI driver to
> + * provide the supported format information.
> + */
> + if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
> + /*
> + * Prepare formats mask for valid/allowed sample types. If the
> + * dma does not have support for the given physical word size,
> + * it needs to be masked out so user space can not use the
> + * format which produces corrupted audio.
> + * In case the dma driver does not implement the slave_caps the
> + * default assumption is that it supports 1, 2 and 4 bytes
> + * widths.
> + */
> + for (i = SNDRV_PCM_FORMAT_FIRST; i <= SNDRV_PCM_FORMAT_LAST; i++) {
> + int bits = snd_pcm_format_physical_width(i);
> +
> + /*
> + * Enable only samples with DMA supported physical
> + * widths
> + */
> + switch (bits) {
> + case 8:
> + case 16:
> + case 24:
> + case 32:
> + case 64:
> + if (addr_widths & (1 << (bits / 8)))
> + hw->formats |= pcm_format_to_bits(i);
> + break;
> + default:
> + /* Unsupported types */
> + break;
> + }
> + }
> +
> + return ret;

... down here.

Where as in the old code...

> diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
> index 748f5f641002..b9f147eaf7c4 100644
> --- a/sound/soc/soc-generic-dmaengine-pcm.c
> +++ b/sound/soc/soc-generic-dmaengine-pcm.c

> @@ -145,56 +140,12 @@ static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substrea
> if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
> hw.info |= SNDRV_PCM_INFO_BATCH;
>
> - ret = dma_get_slave_caps(chan, &dma_caps);
> - if (ret == 0) {
> - if (dma_caps.cmd_pause && dma_caps.cmd_resume)
> - hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
> - if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
> - hw.info |= SNDRV_PCM_INFO_BATCH;
> -
> - if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> - addr_widths = dma_caps.dst_addr_widths;
> - else
> - addr_widths = dma_caps.src_addr_widths;
> - }

...the ret from dma_get_slave_caps() checked above, but is not
actually returned.

Suggestions on how to sort this out?

thanks
-john