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authorLars-Peter Clausen <lars@metafoo.de>2014-01-11 20:08:38 +0100
committerVinod Koul <vinod.koul@intel.com>2014-01-20 13:50:49 +0530
commit04abf5daf7df852566e5a4782d5954daa40e2542 (patch)
tree8bee95188e65e2264633a8ec9ee8bb8bc898913f /drivers/dma/pl330.c
parentba07d812f58c0ec65fff981a085529ed88965d23 (diff)
downloadop-kernel-dev-04abf5daf7df852566e5a4782d5954daa40e2542.zip
op-kernel-dev-04abf5daf7df852566e5a4782d5954daa40e2542.tar.gz
dma: pl330: Differentiate between submitted and issued descriptors
The pl330 dmaengine driver currently does not differentiate between submitted and issued descriptors. It won't start transferring a newly submitted descriptor until issue_pending() is called, but only if it is idle. If it is active and a new descriptor is submitted before it goes idle it will happily start the newly submitted descriptor once all earlier submitted descriptors have been completed. This is not a 100% correct with regards to the dmaengine interface semantics. A descriptor is not supposed to be started until the next issue_pending() call after the descriptor has been submitted. This patch adds a second per channel list that keeps track of the submitted descriptors. Once issue_pending() is called the submitted descriptors are moved to the working list and only descriptors on the working list are started. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/pl330.c')
-rw-r--r--drivers/dma/pl330.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 7adaf3a..8e018a2 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -543,7 +543,9 @@ struct dma_pl330_chan {
/* DMA-Engine Channel */
struct dma_chan chan;
- /* List of to be xfered descriptors */
+ /* List of submitted descriptors */
+ struct list_head submitted_list;
+ /* List of issued descriptors */
struct list_head work_list;
/* List of completed descriptors */
struct list_head completed_list;
@@ -2388,6 +2390,11 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned
pl330_chan_ctrl(pch->pl330_chid, PL330_OP_FLUSH);
/* Mark all desc done */
+ list_for_each_entry(desc, &pch->submitted_list, node) {
+ desc->status = FREE;
+ dma_cookie_complete(&desc->txd);
+ }
+
list_for_each_entry(desc, &pch->work_list , node) {
desc->status = FREE;
dma_cookie_complete(&desc->txd);
@@ -2398,6 +2405,7 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned
dma_cookie_complete(&desc->txd);
}
+ list_splice_tail_init(&pch->submitted_list, &pdmac->desc_pool);
list_splice_tail_init(&pch->work_list, &pdmac->desc_pool);
list_splice_tail_init(&pch->completed_list, &pdmac->desc_pool);
spin_unlock_irqrestore(&pch->lock, flags);
@@ -2456,7 +2464,14 @@ pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
static void pl330_issue_pending(struct dma_chan *chan)
{
- pl330_tasklet((unsigned long) to_pchan(chan));
+ struct dma_pl330_chan *pch = to_pchan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&pch->lock, flags);
+ list_splice_tail_init(&pch->submitted_list, &pch->work_list);
+ spin_unlock_irqrestore(&pch->lock, flags);
+
+ pl330_tasklet((unsigned long)pch);
}
/*
@@ -2483,11 +2498,11 @@ static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
dma_cookie_assign(&desc->txd);
- list_move_tail(&desc->node, &pch->work_list);
+ list_move_tail(&desc->node, &pch->submitted_list);
}
cookie = dma_cookie_assign(&last->txd);
- list_add_tail(&last->node, &pch->work_list);
+ list_add_tail(&last->node, &pch->submitted_list);
spin_unlock_irqrestore(&pch->lock, flags);
return cookie;
@@ -2979,6 +2994,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
else
pch->chan.private = adev->dev.of_node;
+ INIT_LIST_HEAD(&pch->submitted_list);
INIT_LIST_HEAD(&pch->work_list);
INIT_LIST_HEAD(&pch->completed_list);
spin_lock_init(&pch->lock);
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