[PATCH 1/3] dmaengine: xilinx_dma: Check for channel idle state before submitting dma descriptor
Kedareswara rao Appana
appana.durga.rao at xilinx.com
Thu Dec 15 07:11:20 PST 2016
Add channel idle state to ensure that dma descriptor is not
submitted when VDMA engine is in progress.
Signed-off-by: Kedareswara rao Appana <appanad at xilinx.com>
---
drivers/dma/xilinx/xilinx_dma.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 8288fe4..736c2a3 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -321,6 +321,7 @@ struct xilinx_dma_tx_descriptor {
* @cyclic: Check for cyclic transfers.
* @genlock: Support genlock mode
* @err: Channel has errors
+ * @idle: Check for channel idle
* @tasklet: Cleanup work after irq
* @config: Device configuration info
* @flush_on_fsync: Flush on Frame sync
@@ -351,6 +352,7 @@ struct xilinx_dma_chan {
bool cyclic;
bool genlock;
bool err;
+ bool idle;
struct tasklet_struct tasklet;
struct xilinx_vdma_config config;
bool flush_on_fsync;
@@ -966,6 +968,7 @@ static void xilinx_dma_halt(struct xilinx_dma_chan *chan)
chan, dma_ctrl_read(chan, XILINX_DMA_REG_DMASR));
chan->err = true;
}
+ chan->idle = true;
}
/**
@@ -1007,6 +1010,9 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
if (chan->err)
return;
+ if (!chan->idle)
+ return;
+
if (list_empty(&chan->pending_list))
return;
@@ -1110,6 +1116,7 @@ static void xilinx_vdma_start_transfer(struct xilinx_dma_chan *chan)
vdma_desc_write(chan, XILINX_DMA_REG_VSIZE, last->hw.vsize);
}
+ chan->idle = false;
if (!chan->has_sg) {
list_del(&desc->node);
list_add_tail(&desc->node, &chan->active_list);
@@ -1447,6 +1454,7 @@ static irqreturn_t xilinx_dma_irq_handler(int irq, void *data)
if (status & XILINX_DMA_DMASR_FRM_CNT_IRQ) {
spin_lock(&chan->lock);
xilinx_dma_complete_descriptor(chan);
+ chan->idle = true;
chan->start_transfer(chan);
spin_unlock(&chan->lock);
}
@@ -2327,6 +2335,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
chan->has_sg = xdev->has_sg;
chan->desc_pendingcount = 0x0;
chan->ext_addr = xdev->ext_addr;
+ chan->idle = true;
spin_lock_init(&chan->lock);
INIT_LIST_HEAD(&chan->pending_list);
--
2.1.2
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