On Mon, Sep 09, 2019 at 06:33:21PM -0400, Shengjiu Wang wrote:
> There is error "aplay: pcm_write:2023: write error: Input/output error"
> on i.MX8QM/i.MX8QXP platform for S24_3LE format.
>
> In i.MX8QM/i.MX8QXP, the DMA is EDMA, which don't support 24bit
> sample, but we didn't add any constraint, that cause issues.
>
> So we need to query the caps of dma, then update the hw parameters
> according to the caps.
> @@ -285,8 +293,81 @@ static int fsl_asrc_dma_startup(struct snd_pcm_substream
> *substream)
>
> runtime->private_data = pair;
>
> - snd_pcm_hw_constraint_integer(substream->runtime,
> - SNDRV_PCM_HW_PARAM_PERIODS);
> + ret = snd_pcm_hw_constraint_integer(substream->runtime,
> + SNDRV_PCM_HW_PARAM_PERIODS);
> + if (ret < 0) {
> + dev_err(dev, "failed to set pcm hw params periods\n");
> + return ret;
> + }
> +
> + dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
> +
> + /* Request a temp pair, which is release in the end */
> + fsl_asrc_request_pair(1, pair);
Not sure if it'd be practical, but a pair request could fail. Will
probably need to check return value.
And a quick feeling is that below code is mostly identical to what
is in the soc-generic-dmaengine-pcm.c file. So I'm wondering if we
could abstract a helper function somewhere in the ASoC core: Mark?
Thanks
Nicolin
> + tmp_chan = fsl_asrc_get_dma_channel(pair, dir);
> + if (!tmp_chan) {
> + dev_err(dev, "can't get dma channel\n");
> + return -EINVAL;
> + }
> +
> + ret = dma_get_slave_caps(tmp_chan, &dma_caps);
> + if (ret == 0) {
> + if (dma_caps.cmd_pause)
> + snd_imx_hardware.info |= SNDRV_PCM_INFO_PAUSE |
> + SNDRV_PCM_INFO_RESUME;
> + if (dma_caps.residue_granularity <=
> + DMA_RESIDUE_GRANULARITY_SEGMENT)
> + snd_imx_hardware.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;
> + }
> +
> + /*
> + * 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 = 0; 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)))
> + snd_imx_hardware.formats |= (1LL << i);
> + break;
> + default:
> + /* Unsupported types */
> + break;
> + }
> + }
> +
> + if (tmp_chan)
> + dma_release_channel(tmp_chan);
> + fsl_asrc_release_pair(pair);
> +
> snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
>
> return 0;
> --
> 2.21.0
>
