ASoC: zx-i2s: fix harsh noise with 16-bit audio
authorShawn Guo <shawn.guo@linaro.org>
Sat, 27 May 2017 07:50:44 +0000 (15:50 +0800)
committerMark Brown <broonie@kernel.org>
Mon, 29 May 2017 13:17:17 +0000 (14:17 +0100)
The audio parameter setup in zx_i2s_hw_params() works fine with 32-bit
samples, but for 16-bit ones, all we can hear is harsh noises.
As suggested by vendor driver code, DMA burst size and TS width should
always be 32 bits, no matter audio sample is 16-bit or 32-bit.

Follow the suggestion above to fix the harsh noise issue seen with
16-bit audio samples.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
sound/soc/zte/zx-i2s.c

index a865f37..a7f7a56 100644 (file)
@@ -226,11 +226,12 @@ static int zx_i2s_hw_params(struct snd_pcm_substream *substream,
        struct zx_i2s_info *i2s = snd_soc_dai_get_drvdata(socdai);
        struct snd_dmaengine_dai_dma_data *dma_data;
        unsigned int lane, ch_num, len, ret = 0;
+       unsigned int ts_width = 32;
        unsigned long val;
        unsigned long chn_cfg;
 
        dma_data = snd_soc_dai_get_dma_data(socdai, substream);
-       dma_data->addr_width = params_width(params) >> 3;
+       dma_data->addr_width = ts_width >> 3;
 
        val = readl_relaxed(i2s->reg_base + ZX_I2S_TIMING_CTRL);
        val &= ~(ZX_I2S_TIMING_TS_WIDTH_MASK | ZX_I2S_TIMING_DATA_SIZE_MASK |
@@ -251,7 +252,7 @@ static int zx_i2s_hw_params(struct snd_pcm_substream *substream,
                dev_err(socdai->dev, "Unknown data format\n");
                return -EINVAL;
        }
-       val |= ZX_I2S_TIMING_TS_WIDTH(len) | ZX_I2S_TIMING_DATA_SIZE(len);
+       val |= ZX_I2S_TIMING_TS_WIDTH(ts_width) | ZX_I2S_TIMING_DATA_SIZE(len);
 
        ch_num = params_channels(params);
        switch (ch_num) {