Re: [Sound-open-firmware] [PATCH 24/25] dw-dma: handle different cases in irq handler

On Tue, 2017-02-07 at 22:03 +0800, Keyon Jie wrote:

After finished a transfer copy, check for reload channel:

1. if next.size is 0xFFFFFFFF, stop this dma copy;
2. if next.size > 0 but not 0xFFFFFFFF, use next element

magic numbers.

for next copy 3. if we are waiting for pause, pause it; 4. otherwise, reload lli.

Signed-off-by: Keyon Jie yang.jie@linux.intel.com

src/audio/dai.c | 2 +- src/drivers/dw-dma.c | 25 ++++++++++++++----------- src/include/reef/dma.h | 6 ++++++ 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/src/audio/dai.c b/src/audio/dai.c index a9b46a5..e365ed9 100644 --- a/src/audio/dai.c +++ b/src/audio/dai.c @@ -140,7 +140,7 @@ static void dai_dma_cb(void *data, uint32_t type, struct dma_sg_elem *next) if (dma_buffer->avail == 0) { dai_cmd(dev, COMP_CMD_STOP, NULL); /* stop dma immediatly */

• 	next->size = 0xFFFFFFFF;
  

• 	next->size = DMA_RELOAD_STOP_SIZE;
  /* let any waiters know we have completed */
  wait_completed(&dev->pipeline->complete);
  return;
  

diff --git a/src/drivers/dw-dma.c b/src/drivers/dw-dma.c index c073ed5..baa773e 100644 --- a/src/drivers/dw-dma.c +++ b/src/drivers/dw-dma.c @@ -387,7 +387,6 @@ out: static int dw_dma_release(struct dma *dma, int channel) { struct dma_pdata *p = dma_get_drvdata(dma);

• struct dma_sg_elem next; uint32_t flags;

  spin_lock_irq(&dma->lock, flags);

@@ -395,8 +394,6 @@ static int dw_dma_release(struct dma *dma, int channel) trace_dma("Dpr");

if (p->chan[channel].status == DMA_STATUS_PAUSED) {

• if (p->chan[channel].cb && p->chan[channel].cb_type & DMA_IRQ_TYPE_LLIST)
  

• 	p->chan[channel].cb(p->chan[channel].cb_data, DMA_IRQ_TYPE_LLIST, &next);
  

  dw_dma_chan_reload_lli(dma, channel); }

@@ -834,20 +831,26 @@ static void dw_dma_irq_handler(void *data) if ((status_tfr & mask) && (p->chan[i].cb_type & DMA_IRQ_TYPE_LLIST)) {

• 	if (p->chan[i].status == DMA_STATUS_PAUSING) {
  

• 		p->chan[i].status = DMA_STATUS_PAUSED;
  

• 		continue;
  

• 	}
  

• next.size = 0;
  if (p->chan[i].cb)
  	p->chan[i].cb(p->chan[i].cb_data,
  		DMA_IRQ_TYPE_LLIST, &next);
  
  

• 	/* check for reload channel */
  

• 	if (next.size > 0)
  

• 	/* check for reload channel:
  

• 	 * next.size is DMA_RELOAD_STOP_SIZE, stop this dma copy;
  

• 	 * next.size > 0 but not DMA_RELOAD_STOP_SIZE, use next
  

• 	 * element for next copy;
  

• 	 * if we are waiting for pause, pause it;
  

• 	 * otherwise, reload lli
  

• 	 */
  

• 	if (next.size == DMA_RELOAD_STOP_SIZE)
  

• 		continue;
  

• 	else if (next.size > 0)
  	dw_dma_chan_reload_next(dma, i, &next);
  

• 	else
  

• 	else if (p->chan[i].status == DMA_STATUS_PAUSING) {
  

• 		p->chan[i].status = DMA_STATUS_PAUSED;
  

• 		continue;
  

• 	} else
  	dw_dma_chan_reload_lli(dma, i);
  

  }

#if DW_USE_HW_LLI diff --git a/src/include/reef/dma.h b/src/include/reef/dma.h index 6de2ede..273371e 100644 --- a/src/include/reef/dma.h +++ b/src/include/reef/dma.h @@ -59,6 +59,12 @@ #define DMA_IRQ_TYPE_BLOCK (1 << 0) #define DMA_IRQ_TYPE_LLIST (1 << 1)

+/* We will use this macro in cb handler to inform dma that

• • we need to stop the reload for specail purpose
• */

+#define DMA_RELOAD_STOP_SIZE 0xFFFFFFFF

if we are using the size variable then it makes more sense to use 0 here to indicate end of transfer.

#define DMA_RELOAD_END 0

struct dma;

struct dma_sg_elem {