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Commit 8d1b76f0 authored by M'boumba Cedric Madianga's avatar M'boumba Cedric Madianga Committed by Vinod Koul
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dmaengine: stm32-dma: Rework starting transfer management 



This patch reworks the way to manage transfer starting.
Now, starting DMA is only allowed when the channel is not busy.
Then, stm32_dma_start_transfer is declared as void.
At least, after each transfer completion, we start the next transfer if a
new descriptor as been queued in the issued list during an ongoing
transfer.

Signed-off-by: default avatarM'boumba Cedric Madianga <cedric.madianga@gmail.com>
Reviewed-by: default avatarLudovic BARRE <ludovic.barre@st.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 16545502

drivers/dma/stm32-dma.c

+9 −11
Original line number Diff line number Diff line
@@ -421,7 +421,7 @@ static void stm32_dma_dump_reg(struct stm32_dma_chan *chan) 
	dev_dbg(chan2dev(chan), "SFCR:  0x%08x\n", sfcr);

}



static int stm32_dma_start_transfer(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);

	struct virt_dma_desc *vdesc;
@@ -432,12 +432,12 @@ static int stm32_dma_start_transfer(struct stm32_dma_chan *chan) 


	ret = stm32_dma_disable_chan(chan);

	if (ret < 0)

		return ret;

		return;



	if (!chan->desc) {

		vdesc = vchan_next_desc(&chan->vchan);

		if (!vdesc)

			return -EPERM;

			return;



		chan->desc = to_stm32_dma_desc(vdesc);

		chan->next_sg = 0;
@@ -471,7 +471,7 @@ static int stm32_dma_start_transfer(struct stm32_dma_chan *chan) 


	chan->busy = true;



	return 0;

	dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);

}



static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
@@ -552,16 +552,14 @@ static void stm32_dma_issue_pending(struct dma_chan *c) 
{

	struct stm32_dma_chan *chan = to_stm32_dma_chan(c);

	unsigned long flags;

	int ret;



	spin_lock_irqsave(&chan->vchan.lock, flags);

	if (!chan->busy) {

		if (vchan_issue_pending(&chan->vchan) && !chan->desc) {

			ret = stm32_dma_start_transfer(chan);

			if ((!ret) && (chan->desc->cyclic))

	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);

}