Re: [PATCH 1/2] ASoC: davinci: Clear VCIF read FIFO on errors

From: Peter Ujfalusi
Date: Fri Apr 10 2015 - 03:21:39 EST


On 04/10/2015 02:00 AM, Alexey Ignatov wrote:
> Clearing VCIF read FIFO on overflow and underflow events fixes audio glitching
> when DMA load is high. This happened when simultaneously capturing and encoding
> video and audio, for example.
>
> Signed-off-by: Alexey Ignatov <lexszero@xxxxxxxxx>
> ---
> sound/soc/davinci/davinci-vcif.c | 60 +++++++++++++++++++++++++++++++++++++---
> 1 file changed, 56 insertions(+), 4 deletions(-)
>
> diff --git a/sound/soc/davinci/davinci-vcif.c b/sound/soc/davinci/davinci-vcif.c
> index 5bee0427..0d8014e 100644
> --- a/sound/soc/davinci/davinci-vcif.c
> +++ b/sound/soc/davinci/davinci-vcif.c
> @@ -45,6 +45,10 @@
> } \
> } while (0)
>
> +#define DAVINCI_VC_INT_RERR_MASK \
> + (DAVINCI_VC_INT_RERRUDR_MASK | \
> + DAVINCI_VC_INT_RERROVF_MASK)
> +
> struct davinci_vcif_dev {
> struct davinci_vc *davinci_vc;
> struct davinci_pcm_dma_params dma_params[2];
> @@ -87,6 +91,22 @@ static void davinci_vcif_stop(struct snd_pcm_substream *substream)
> writel(w, davinci_vc->base + DAVINCI_VC_CTRL);
> }
>
> +static void davinci_vcif_interrupts(struct snd_pcm_substream *substream,
> + int enable)
> +{
> + struct snd_soc_pcm_runtime *rtd = substream->private_data;
> + struct davinci_vcif_dev *davinci_vcif_dev =
> + snd_soc_dai_get_drvdata(rtd->cpu_dai);
> + struct davinci_vc *davinci_vc = davinci_vcif_dev->davinci_vc;
> +
> + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
> + writel(DAVINCI_VC_INT_RERR_MASK,
> + davinci_vc->base + DAVINCI_VC_INTCLR);
> + writel(enable ? DAVINCI_VC_INT_RERR_MASK : 0,
> + davinci_vc->base + DAVINCI_VC_INTEN);
> + }
> +}
> +
> static int davinci_vcif_hw_params(struct snd_pcm_substream *substream,
> struct snd_pcm_hw_params *params,
> struct snd_soc_dai *dai)
> @@ -104,10 +124,6 @@ static int davinci_vcif_hw_params(struct snd_pcm_substream *substream,
> /* General line settings */
> writel(DAVINCI_VC_CTRL_MASK, davinci_vc->base + DAVINCI_VC_CTRL);
>
> - writel(DAVINCI_VC_INT_MASK, davinci_vc->base + DAVINCI_VC_INTCLR);
> -
> - writel(DAVINCI_VC_INT_MASK, davinci_vc->base + DAVINCI_VC_INTEN);
> -
> w = readl(davinci_vc->base + DAVINCI_VC_CTRL);
>
> /* Determine xfer data type */
> @@ -149,6 +165,32 @@ static int davinci_vcif_hw_params(struct snd_pcm_substream *substream,
> return 0;
> }
>
> +static irqreturn_t davinci_vcif_irq_handler(int irq, void *data)
> +{
> + struct davinci_vcif_dev *davinci_vcif_dev = data;
> + struct davinci_vc *davinci_vc = davinci_vcif_dev->davinci_vc;
> + uint32_t w;
> +
> + w = readl(davinci_vc->base + DAVINCI_VC_INTSTATUS);
> +
> + if (w & DAVINCI_VC_INT_RERR_MASK) {
> + pr_debug("vc overflow or underflow occurred, resetting fifo\n");
> +
> + w = readl(davinci_vc->base + DAVINCI_VC_CTRL);
> + MOD_REG_BIT(w, DAVINCI_VC_CTRL_RFIFOCL, 1);
> + writel(w, davinci_vc->base + DAVINCI_VC_CTRL);
> +
> + w = readl(davinci_vc->base + DAVINCI_VC_CTRL);
> + MOD_REG_BIT(w, DAVINCI_VC_CTRL_RFIFOCL, 0);
> + writel(w, davinci_vc->base + DAVINCI_VC_CTRL);
> +
> + writel(DAVINCI_VC_INT_RERR_MASK,
> + davinci_vc->base + DAVINCI_VC_INTCLR);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> static int davinci_vcif_trigger(struct snd_pcm_substream *substream, int cmd,
> struct snd_soc_dai *dai)
> {
> @@ -159,10 +201,12 @@ static int davinci_vcif_trigger(struct snd_pcm_substream *substream, int cmd,
> case SNDRV_PCM_TRIGGER_RESUME:
> case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
> davinci_vcif_start(substream);
> + davinci_vcif_interrupts(substream, 1);
> break;
> case SNDRV_PCM_TRIGGER_STOP:
> case SNDRV_PCM_TRIGGER_SUSPEND:
> case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
> + davinci_vcif_interrupts(substream, 0);
> davinci_vcif_stop(substream);
> break;
> default:
> @@ -178,6 +222,7 @@ static int davinci_vcif_startup(struct snd_pcm_substream *substream,
> struct davinci_vcif_dev *dev = snd_soc_dai_get_drvdata(dai);
>
> snd_soc_dai_set_dma_data(dai, substream, dev->dma_params);
> +
> return 0;
> }
>
> @@ -238,6 +283,13 @@ static int davinci_vcif_probe(struct platform_device *pdev)
>
> dev_set_drvdata(&pdev->dev, davinci_vcif_dev);
>
> + ret = devm_request_irq(&pdev->dev, IRQ_MBXINT, davinci_vcif_irq_handler,
> + 0, "vcif", davinci_vcif_dev);
> + if (ret != 0) {
> + dev_err(&pdev->dev, "could not request irq: %d\n", ret);
> + return ret;
> + }

I would make this optional to avoid regression if the arch patch is not present.

> +
> ret = snd_soc_register_component(&pdev->dev, &davinci_vcif_component,
> &davinci_vcif_dai, 1);
> if (ret != 0) {
>


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