From 26c5e36931b3fea7461ba6f0d8b65eb25ce2b917 Mon Sep 17 00:00:00 2001 From: Kedareswara rao Appana Date: Fri, 26 Feb 2016 19:33:52 +0530 Subject: dmaengine: xilinx_vdma: Simplify spin lock handling This patch simplifies the spin lock handling in the driver by moving locking out of xilinx_dma_start_transfer() API and xilinx_dma_update_completed_cookie() API. Signed-off-by: Kedareswara rao Appana Signed-off-by: Vinod Koul --- drivers/dma/xilinx/xilinx_vdma.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) (limited to 'drivers/dma') diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c index e96ff9dea40d..70b2b32cba15 100644 --- a/drivers/dma/xilinx/xilinx_vdma.c +++ b/drivers/dma/xilinx/xilinx_vdma.c @@ -605,17 +605,15 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan) { struct xilinx_vdma_config *config = &chan->config; struct xilinx_vdma_tx_descriptor *desc, *tail_desc; - unsigned long flags; u32 reg; struct xilinx_vdma_tx_segment *tail_segment; + /* This function was invoked with lock held */ if (chan->err) return; - spin_lock_irqsave(&chan->lock, flags); - if (list_empty(&chan->pending_list)) - goto out_unlock; + return; desc = list_first_entry(&chan->pending_list, struct xilinx_vdma_tx_descriptor, node); @@ -629,7 +627,7 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan) if (chan->has_sg && xilinx_vdma_is_running(chan) && !xilinx_vdma_is_idle(chan)) { dev_dbg(chan->dev, "DMA controller still busy\n"); - goto out_unlock; + return; } /* @@ -680,7 +678,7 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan) xilinx_vdma_start(chan); if (chan->err) - goto out_unlock; + return; /* Start the transfer */ if (chan->has_sg) { @@ -700,7 +698,7 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan) } if (!last) - goto out_unlock; + return; /* HW expects these parameters to be same for one transaction */ vdma_desc_write(chan, XILINX_VDMA_REG_HSIZE, last->hw.hsize); @@ -711,9 +709,6 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan) list_splice_tail_init(&chan->pending_list, &chan->active_list); chan->desc_pendingcount = 0; - -out_unlock: - spin_unlock_irqrestore(&chan->lock, flags); } /** @@ -723,8 +718,11 @@ out_unlock: static void xilinx_vdma_issue_pending(struct dma_chan *dchan) { struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan); + unsigned long flags; + spin_lock_irqsave(&chan->lock, flags); xilinx_vdma_start_transfer(chan); + spin_unlock_irqrestore(&chan->lock, flags); } /** @@ -736,21 +734,16 @@ static void xilinx_vdma_issue_pending(struct dma_chan *dchan) static void xilinx_vdma_complete_descriptor(struct xilinx_vdma_chan *chan) { struct xilinx_vdma_tx_descriptor *desc, *next; - unsigned long flags; - - spin_lock_irqsave(&chan->lock, flags); + /* This function was invoked with lock held */ if (list_empty(&chan->active_list)) - goto out_unlock; + return; list_for_each_entry_safe(desc, next, &chan->active_list, node) { list_del(&desc->node); dma_cookie_complete(&desc->async_tx); list_add_tail(&desc->node, &chan->done_list); } - -out_unlock: - spin_unlock_irqrestore(&chan->lock, flags); } /** @@ -861,8 +854,10 @@ static irqreturn_t xilinx_vdma_irq_handler(int irq, void *data) } if (status & XILINX_VDMA_DMASR_FRM_CNT_IRQ) { + spin_lock(&chan->lock); xilinx_vdma_complete_descriptor(chan); xilinx_vdma_start_transfer(chan); + spin_unlock(&chan->lock); } tasklet_schedule(&chan->tasklet); -- cgit v1.2.3-59-g8ed1b