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| author | M'boumba Cedric Madianga <cedric.madianga@gmail.com> | 2016-12-13 16:40:47 +0300 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2017-01-03 06:53:17 +0300 |
| commit | 8d1b76f031ce60c50d03674e6d1db0c5e5f55945 (patch) | |
| tree | 9d676e6303fd3255e129a91011dce9a36bd28c36 /drivers/dma | |
| parent | 16545502d70641af0fc4d2cc0b2789cf27d9ca9d (diff) | |
| download | linux-8d1b76f031ce60c50d03674e6d1db0c5e5f55945.tar.xz | |
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: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Reviewed-by: Ludovic BARRE <ludovic.barre@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/stm32-dma.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c index 3688d0873a3e..a8c2ad686173 100644 --- a/drivers/dma/stm32-dma.c +++ b/drivers/dma/stm32-dma.c @@ -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) @@ -552,15 +552,13 @@ 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)) - stm32_dma_configure_next_sg(chan); - } + 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); } |