diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index b9629b2bfc05..d1651a50c349 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -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;