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Commit b006c34f authored by Nandor Han's avatar Nandor Han Committed by android-build-merger
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dmaengine: imx-sdma - correct the dma transfer residue calculation 

am: 3a654a85

Change-Id: I02761c73b18a16b3de0fed6f9c0fd0a7c754e8d0
parents 5565d5e5 3a654a85

drivers/dma/imx-sdma.c

+9 −4
Original line number Diff line number Diff line
@@ -298,6 +298,7 @@ struct sdma_engine; 
 * @event_id1		for channels that use 2 events

 * @word_size		peripheral access size

 * @buf_tail		ID of the buffer that was processed

 * @buf_ptail		ID of the previous buffer that was processed

 * @num_bd		max NUM_BD. number of descriptors currently handling

 */

struct sdma_channel {
@@ -309,6 +310,7 @@ struct sdma_channel { 
	unsigned int			event_id1;

	enum dma_slave_buswidth		word_size;

	unsigned int			buf_tail;

	unsigned int			buf_ptail;

	unsigned int			num_bd;

	unsigned int			period_len;

	struct sdma_buffer_descriptor	*bd;
@@ -700,6 +702,8 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) 
		sdmac->chn_real_count = bd->mode.count;

		bd->mode.status |= BD_DONE;

		bd->mode.count = sdmac->period_len;

		sdmac->buf_ptail = sdmac->buf_tail;

		sdmac->buf_tail = (sdmac->buf_tail + 1) % sdmac->num_bd;



		/*

		 * The callback is called from the interrupt context in order
@@ -710,9 +714,6 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) 


		dmaengine_desc_get_callback_invoke(&sdmac->desc, NULL);



		sdmac->buf_tail++;

		sdmac->buf_tail %= sdmac->num_bd;



		if (error)

			sdmac->status = old_status;

	}
@@ -1186,6 +1187,8 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg( 
	sdmac->flags = 0;



	sdmac->buf_tail = 0;

	sdmac->buf_ptail = 0;

	sdmac->chn_real_count = 0;



	dev_dbg(sdma->dev, "setting up %d entries for channel %d.\n",

			sg_len, channel);
@@ -1288,6 +1291,8 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic( 
	sdmac->status = DMA_IN_PROGRESS;



	sdmac->buf_tail = 0;

	sdmac->buf_ptail = 0;

	sdmac->chn_real_count = 0;

	sdmac->period_len = period_len;



	sdmac->flags |= IMX_DMA_SG_LOOP;
@@ -1385,7 +1390,7 @@ static enum dma_status sdma_tx_status(struct dma_chan *chan, 
	u32 residue;



	if (sdmac->flags & IMX_DMA_SG_LOOP)

		residue = (sdmac->num_bd - sdmac->buf_tail) *

		residue = (sdmac->num_bd - sdmac->buf_ptail) *

			   sdmac->period_len - sdmac->chn_real_count;

	else

		residue = sdmac->chn_count - sdmac->chn_real_count;