Re: [alsa-devel] [PATCH 1/6] ASoC/mpc5200: Track DMA position by period number instead of bytes

On Sat, 2009-11-07 at 01:33 -0700, Grant Likely wrote:

All DMA blocks are lined up to period boundaries, but the DMA handling code tracks bytes instead. This patch reworks the code to track the period index into the DMA buffer instead of the physical address pointer. Doing so makes the code simpler and easier to understand.

Signed-off-by: Grant Likely grant.likely@secretlab.ca

Very minor coding style thing below otherwise all get my Ack.

Acked-by: Liam Girdwood lrg@slimlogic.co.uk

---

sound/soc/fsl/mpc5200_dma.c | 28 +++++++++------------------- sound/soc/fsl/mpc5200_dma.h | 8 ++------ 2 files changed, 11 insertions(+), 25 deletions(-)

diff --git a/sound/soc/fsl/mpc5200_dma.c b/sound/soc/fsl/mpc5200_dma.c index 6096d22..986d3c8 100644 --- a/sound/soc/fsl/mpc5200_dma.c +++ b/sound/soc/fsl/mpc5200_dma.c @@ -58,13 +58,11 @@ static void psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream *s) /* Prepare and enqueue the next buffer descriptor */ bd = bcom_prepare_next_buffer(s->bcom_task); bd->status = s->period_bytes;

• bd->data[0] = s->period_next_pt;

• bd->data[0] = s->runtime->dma_addr + (s->period_next * s->period_bytes); bcom_submit_next_buffer(s->bcom_task, NULL);

  /* Update for next period */

• s->period_next_pt += s->period_bytes;
• if (s->period_next_pt >= s->period_end)

• s->period_next_pt = s->period_start;
  

• s->period_next = (s->period_next + 1) % s->runtime->periods;

}

static void psc_dma_bcom_enqueue_tx(struct psc_dma_stream *s) @@ -79,7 +77,7 @@ static void psc_dma_bcom_enqueue_tx(struct psc_dma_stream *s) if (bcom_queue_full(s->bcom_task)) return;

• 	s->appl_ptr += s->period_size;
  

• 	s->appl_ptr += s->runtime->period_size;
  
  psc_dma_bcom_enqueue_next_buffer(s);
  

  }

@@ -91,7 +89,7 @@ static void psc_dma_bcom_enqueue_tx(struct psc_dma_stream *s) if (bcom_queue_full(s->bcom_task)) return;

• s->appl_ptr += s->period_size;
  

• s->appl_ptr += s->runtime->period_size;
  
  

  psc_dma_bcom_enqueue_next_buffer(s); }

@@ -108,9 +106,7 @@ static irqreturn_t psc_dma_bcom_irq_tx(int irq, void *_psc_dma_stream) while (bcom_buffer_done(s->bcom_task)) { bcom_retrieve_buffer(s->bcom_task, NULL, NULL);

• s->period_current_pt += s->period_bytes;
  

• if (s->period_current_pt >= s->period_end)
  

• 	s->period_current_pt = s->period_start;
  

• s->period_current = (s->period_current+1) % s->runtime->periods;
  

I prefer a space around operators.

s->period_current = (s->period_current + 1) % s->runtime->periods;

Liam