This patch makes snd_dmaengine_pcm_register with rockchip_dmaengine_pcm_config, which configure the parameters of period and buffer match to rockchip DMAC.

======================= without rockchip_dmaengine_pcm_config, and test with command - aplay -D hw:0,0 /tmp/a, there are the error dump: [ 134.899396] dma-pl330 ffb20000.dma-controller: fill_queue:2251 Bad Desc(7) [ 134.906270] dma-pl330 ffb20000.dma-controller: fill_queue:2251 Bad Desc(8) [ 134.913141] dma-pl330 ffb20000.dma-controller: fill_queue:2251 Bad Desc(9)

And bellow sound from DMA debugger: "I debugged it a little and it looks like what is happening is that requests which aren't a multiple of burst size * burst length are coming in. Right now the i2s block is setting a burst size of 4 and burst length of 4, but the dmaengine code has no idea about this restriction. I was able to eliminate the messages by changing burst length to 1 in the i2s driver. This fix would always work as long as we're sending a multiple of 4 bytes (which so far seems to be the case)"

This patch can make the length of dma buffer is aligned to a multiple of burst size and burst length.

Signed-off-by: Jianqun Xu jay.xu@rock-chips.com --- sound/soc/rockchip/rockchip_i2s.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c index c74ba37..bdd1021 100644 --- a/sound/soc/rockchip/rockchip_i2s.c +++ b/sound/soc/rockchip/rockchip_i2s.c @@ -408,6 +408,24 @@ static const struct regmap_config rockchip_i2s_regmap_config = { .cache_type = REGCACHE_FLAT, };

+static const struct snd_pcm_hardware rockchip_pcm_hardware = { + .info = SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_INTERLEAVED, + .period_bytes_min = 1024, + .period_bytes_max = PAGE_SIZE, + .periods_min = 3, + .periods_max = 8, + .buffer_bytes_max = 8 * PAGE_SIZE, + .fifo_size = 16, +}; + +static const struct snd_dmaengine_pcm_config rockchip_dmaengine_pcm_config = { + .pcm_hardware = &rockchip_pcm_hardware, + .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config, + .prealloc_buffer_size = PAGE_SIZE * 8, +}; + static int rockchip_i2s_probe(struct platform_device *pdev) { struct rk_i2s_dev *i2s; @@ -478,7 +496,8 @@ static int rockchip_i2s_probe(struct platform_device *pdev) goto err_suspend; }

- ret = snd_dmaengine_pcm_register(&pdev->dev, NULL, 0); + ret = snd_dmaengine_pcm_register(&pdev->dev, + &rockchip_dmaengine_pcm_config, 0); if (ret) { dev_err(&pdev->dev, "Could not register PCM\n"); goto err_pcm_register;