diff options
| -rw-r--r-- | drivers/dma/stm32-dma.c | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index a8c2ad686173..8a29b028d39e 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -500,8 +500,6 @@ static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan) dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n", stm32_dma_read(dmadev, STM32_DMA_SM1AR(id))); } - - chan->next_sg++; } } @@ -510,6 +508,7 @@ static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan) if (chan->desc) { if (chan->desc->cyclic) { vchan_cyclic_callback(&chan->desc->vdesc); + chan->next_sg++; stm32_dma_configure_next_sg(chan); } else { chan->busy = false; @@ -846,26 +845,40 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy( return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); } +static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan) +{ + u32 dma_scr, width, ndtr; + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + + dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id)); + width = STM32_DMA_SCR_PSIZE_GET(dma_scr); + ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id)); + + return ndtr << width; +} + static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan, struct stm32_dma_desc *desc, u32 next_sg) { - struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); - u32 dma_scr, width, residue, count; + u32 residue = 0; int i; - residue = 0; + /* + * In cyclic mode, for the last period, residue = remaining bytes from + * NDTR + */ + if (chan->desc->cyclic && next_sg == 0) + return stm32_dma_get_remaining_bytes(chan); + /* + * For all other periods in cyclic mode, and in sg mode, + * residue = remaining bytes from NDTR + remaining periods/sg to be + * transferred + */ for (i = next_sg; i < desc->num_sgs; i++) residue += desc->sg_req[i].len; - - if (next_sg != 0) { - dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id)); - width = STM32_DMA_SCR_PSIZE_GET(dma_scr); - count = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id)); - - residue += count << width; - } + residue += stm32_dma_get_remaining_bytes(chan); return residue; } |