dw-dma: use ll_current on dma start

On starting GPDMA we should use current link list item.
That way every start will continue from the right buffer,
not causing data corruption due to writing to the same
period as Host DMA.

Signed-off-by: Tomasz Lauda <tomasz.lauda@linux.intel.com>

Author: tlauda

src/drivers/dw-dma.c

@@ -405,26 +405,28 @@ static int dw_dma_start(struct dma *dma, int channel)
 
 #if DW_USE_HW_LLI
 	/* TODO: Revisit: are we using LLP mode or single transfer ? */
-	if (p->chan[channel].lli) {
+	if (p->chan[channel].lli_current) {
 		/* LLP mode - write LLP pointer */
-		dw_write(dma, DW_LLP(channel), (uint32_t)p->chan[channel].lli);
+		dw_write(dma, DW_LLP(channel),
+			 (uint32_t)p->chan[channel].lli_current);
 	}
 #endif
 	/* channel needs started from scratch, so write SARn, DARn */
-	dw_write(dma, DW_SAR(channel), p->chan[channel].lli->sar);
-	dw_write(dma, DW_DAR(channel), p->chan[channel].lli->dar);
+	dw_write(dma, DW_SAR(channel), p->chan[channel].lli_current->sar);
+	dw_write(dma, DW_DAR(channel), p->chan[channel].lli_current->dar);
 
 	/* program CTLn */
-	dw_write(dma, DW_CTRL_LOW(channel), p->chan[channel].lli->ctrl_lo);
-	dw_write(dma, DW_CTRL_HIGH(channel), p->chan[channel].lli->ctrl_hi);
+	dw_write(dma, DW_CTRL_LOW(channel),
+		 p->chan[channel].lli_current->ctrl_lo);
+	dw_write(dma, DW_CTRL_HIGH(channel),
+		 p->chan[channel].lli_current->ctrl_hi);
 
 	/* write channel config */
 	dw_write(dma, DW_CFG_LOW(channel), p->chan[channel].cfg_lo);
 	dw_write(dma, DW_CFG_HIGH(channel), p->chan[channel].cfg_hi);
 
 	/* enable the channel */
 	p->chan[channel].status = COMP_STATE_ACTIVE;
-	p->chan[channel].lli_current = p->chan[channel].lli;
 	dw_write(dma, DW_DMA_CHAN_EN, CHAN_ENABLE(channel));
 
 out:
@@ -745,6 +747,7 @@ static int dw_dma_set_config(struct dma *dma, int channel,
 			sizeof(struct dw_lli2) * p->chan[channel].desc_count);
 
 	p->chan[channel].status = COMP_STATE_PREPARE;
+	p->chan[channel].lli_current = p->chan[channel].lli;
 out:
 	spin_unlock_irq(&dma->lock, flags);
 	return ret;
@@ -949,24 +952,25 @@ static void dw_dma_irq_handler(void *data)
 		return;
 	}
 
-
 #if DW_USE_HW_LLI
-		/* end of a LLI block */
-		if (status_block & mask &&
-		    p->chan[i].cb_type & DMA_IRQ_TYPE_BLOCK) {
-			next.src = DMA_RELOAD_LLI;
-			next.dest = DMA_RELOAD_LLI;
-			/* will reload lli by default */
-			next.size = DMA_RELOAD_LLI;
-			p->chan[i].cb(p->chan[i].cb_data,
-					DMA_IRQ_TYPE_BLOCK, &next);
-			if (next.size == DMA_RELOAD_END) {
-				trace_dma("LSo");
-				/* disable channel, finished */
-				dw_write(dma, DW_DMA_CHAN_EN, CHAN_DISABLE(i));
-				p->chan[i].status = COMP_STATE_PREPARE;
-			}
+	/* end of a LLI block */
+	if (status_block & mask &&
+	    p->chan[i].cb_type & DMA_IRQ_TYPE_BLOCK) {
+		next.src = DMA_RELOAD_LLI;
+		next.dest = DMA_RELOAD_LLI;
+		/* will reload lli by default */
+		next.size = DMA_RELOAD_LLI;
+		p->chan[i].cb(p->chan[i].cb_data,
+				DMA_IRQ_TYPE_BLOCK, &next);
+		if (next.size == DMA_RELOAD_END) {
+			trace_dma("LSo");
+			/* disable channel, finished */
+			dw_write(dma, DW_DMA_CHAN_EN, CHAN_DISABLE(i));
+			p->chan[i].status = COMP_STATE_PREPARE;
 		}
+		p->chan[i].lli_current =
+			(struct dw_lli2 *)p->chan[i].lli_current->llp;
+	}
 #endif
 	/* end of a transfer */
 	if ((status_tfr & mask) &&
@@ -1117,6 +1121,8 @@ static void dw_dma_irq_handler(void *data)
 				dw_write(dma, DW_DMA_CHAN_EN, CHAN_DISABLE(i));
 				p->chan[i].status = COMP_STATE_PREPARE;
 			}
+			p->chan[i].lli_current =
+				(struct dw_lli2 *)p->chan[i].lli_current->llp;
 		}
 #endif
 		/* end of a transfer */