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[4.2] fix cyclic dma setup and i2s parameters #1193

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[4.2] fix cyclic dma setup and i2s parameters #1193

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8229b0e
bcm2835-dma: fix calculation of cyclic DMA frames
HiassofT Nov 8, 2015
380ee56
Revert "bcm2835-dma: Limit cyclic transfers on lite channels to 32k"
HiassofT Nov 8, 2015
0d53dfc
bcm2835-i2s: match period_bytes_max to DMA controller limit
HiassofT Nov 8, 2015
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10 changes: 2 additions & 8 deletions drivers/dma/bcm2835-dma.c
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Original file line number Diff line number Diff line change
Expand Up @@ -141,12 +141,6 @@ struct bcm2835_desc {
*/
#define MAX_LITE_TRANSFER (SZ_64K - 4)

/*
* Transfers larger than 32k cause issues with the bcm2708-i2s driver,
* so limit transfer size to 32k as bcm2708-dmaengine did.
*/
#define MAX_CYCLIC_LITE_TRANSFER SZ_32K

static inline struct bcm2835_dmadev *to_bcm2835_dma_dev(struct dma_device *d)
{
return container_of(d, struct bcm2835_dmadev, ddev);
Expand Down Expand Up @@ -403,11 +397,11 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(

d->dir = direction;
if (c->ch >= 8) /* LITE channel */
max_size = MAX_CYCLIC_LITE_TRANSFER;
max_size = MAX_LITE_TRANSFER;
else
max_size = MAX_NORMAL_TRANSFER;
period_len = min(period_len, max_size);
d->frames = (buf_len - 1) / (period_len + 1);
d->frames = DIV_ROUND_UP(buf_len, period_len);

/* Allocate memory for control blocks */
d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb);
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6 changes: 3 additions & 3 deletions sound/soc/bcm/bcm2835-i2s.c
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Expand Up @@ -806,16 +806,16 @@ static struct snd_pcm_hardware bcm2835_pcm_hardware = {
SNDRV_PCM_FMTBIT_S24_LE |
SNDRV_PCM_FMTBIT_S32_LE,
.period_bytes_min = 32,
.period_bytes_max = 64 * PAGE_SIZE,
.period_bytes_max = SZ_64K - 4,
.periods_min = 2,
.periods_max = 255,
.buffer_bytes_max = 128 * PAGE_SIZE,
.buffer_bytes_max = SZ_512K,
};

static const struct snd_dmaengine_pcm_config bcm2835_dmaengine_pcm_config = {
.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
.pcm_hardware = &bcm2835_pcm_hardware,
.prealloc_buffer_size = 256 * PAGE_SIZE,
.prealloc_buffer_size = SZ_1M,
};

static int bcm2835_i2s_probe(struct platform_device *pdev)
Expand Down