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authorKedareswara rao Appana <appana.durga.rao@xilinx.com>2016-02-26 19:33:52 +0530
committerVinod Koul <vinod.koul@intel.com>2016-03-03 21:02:38 +0530
commit26c5e36931b3fea7461ba6f0d8b65eb25ce2b917 (patch)
tree3e386ab19e856703a1fcde0c5cadd6750eb7ebd7 /drivers/dma
parente2b538a77d99706a9d2dc12925f3f8477c724dcc (diff)
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 <appanad@xilinx.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/xilinx/xilinx_vdma.c29
1 files changed, 12 insertions, 17 deletions
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);