[PATCH v1 7/8] dmaengine: stm32-dma: fix incomplete configuration in cyclic mode

From: Pierre-Yves MORDRET
Date: Tue Mar 13 2018 - 12:43:25 EST


When in cyclic mode, the configuration is updated after having started the
DMA hardware (STM32_DMA_SCR_EN) leading to incomplete configuration of
SMxAR registers.

Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@xxxxxx>
Signed-off-by: Hugues Fruchet <hugues.fruchet@xxxxxx>
---
Version history:
v1:
* Initial
---
---
drivers/dma/stm32-dma.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index a11cbee..38c545d 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -538,6 +538,8 @@ static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
}

+static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan);
+
static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
@@ -580,6 +582,9 @@ static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
if (status)
stm32_dma_irq_clear(chan, status);

+ if (chan->desc->cyclic)
+ stm32_dma_configure_next_sg(chan);
+
stm32_dma_dump_reg(chan);

/* Start DMA */
@@ -689,8 +694,7 @@ static void stm32_dma_issue_pending(struct dma_chan *c)
if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
stm32_dma_start_transfer(chan);
- if (chan->desc->cyclic)
- stm32_dma_configure_next_sg(chan);
+
}
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
--
2.7.4