dai: stop DMA unconditionally on xrun

Stops DMA unconditionally on xrun without waiting.
Data flush is not needed as pipeline will go through
prepare and restart anyway. Waiting here during xrun
recovery with multiple tasks running causes interrupt
stack overflow. Waiti instruction lowers irq level to
0, which allows to run multiple scheduled tasks in the
same time on the same irq level and ends in DSP panic.

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

src/audio/dai.c

@@ -596,7 +596,12 @@ static int dai_comp_trigger(struct comp_dev *dev, int cmd)
 		break;
 	case COMP_TRIGGER_XRUN:
 		dd->xrun = 1;
-		/* fall through */
+		/* stop the DAI unconditionally */
+		dai_trigger(dd->dai, COMP_TRIGGER_STOP, dev->params.direction);
+		ret = dma_stop(dd->dma, dd->chan);
+		if (ret < 0)
+			return ret;
+		break;
 	case COMP_TRIGGER_PAUSE:
 	case COMP_TRIGGER_STOP:
 		wait_init(&dd->complete);

src/drivers/dw-dma.c

@@ -484,19 +484,30 @@ static int dw_dma_pause(struct dma *dma, int channel)
 static int dw_dma_stop(struct dma *dma, int channel)
 {
 	struct dma_pdata *p = dma_get_drvdata(dma);
-	int  ret = 0;
+	int ret = 0;
+	int i = 0;
+	struct dw_lli2 *lli;
 	uint32_t flags;
 
 	spin_lock_irq(&dma->lock, flags);
 
 	trace_dma("DDi");
 
-	/* is channel stii active ? */
-	if ((dw_read(dma, DW_DMA_CHAN_EN) & (0x1 << channel))) {
-		trace_dma_error("ea0");
-		trace_error_value(channel);
+	dw_write(dma, DW_DMA_CHAN_EN, CHAN_DISABLE(channel));
+
+#if DW_USE_HW_LLI
+	for (i = 0; i < p->chan[channel].desc_count; i++) {
+		lli = p->chan[channel].lli;
+		lli->ctrl_hi &= ~DW_CTLH_DONE(1);
+		lli++;
 	}
 
+	dcache_writeback_region(p->chan[channel].lli,
+			sizeof(struct dw_lli2) * p->chan[channel].desc_count);
+#endif
+
+	dw_write(dma, DW_CLEAR_BLOCK, 0x1 << channel);
+
 	p->chan[channel].status = COMP_STATE_PREPARE;
 
 	spin_unlock_irq(&dma->lock, flags);