[PATCH 2/8] dmaengine: amba-pl08x: ensure physical channels are properly held

[Russell King]

Ensure that physical channels are held while there are descriptors for
them to process.  This is needed when we split the pending queue into
separate pending and issued queues.

Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
 drivers/dma/amba-pl08x.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index c301a8e..2e74cca 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -855,6 +855,8 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
 	struct pl08x_phy_chan *ch;
 	int ret;
 
+	plchan->phychan_hold++;
+
 	/* Check if we already have a channel */
 	if (plchan->phychan) {
 		ch = plchan->phychan;
@@ -863,6 +865,7 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
 
 	ch = pl08x_get_phy_channel(pl08x, plchan);
 	if (!ch) {
+		plchan->phychan_hold--;
 		/* No physical channel available, cope with it */
 		dev_dbg(&pl08x->adev->dev, "no physical channel available for xfer on %s\n", plchan->name);
 		return -EBUSY;
@@ -876,6 +879,7 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
 	if (plchan->slave && pl08x->pd->get_signal) {
 		ret = pl08x->pd->get_signal(plchan);
 		if (ret < 0) {
+			plchan->phychan_hold--;
 			dev_dbg(&pl08x->adev->dev,
 				"unable to use physical channel %d for transfer on %s due to platform restrictions\n",
 				ch->id, plchan->name);
@@ -899,8 +903,6 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
 	else if (txd->direction == DMA_DEV_TO_MEM)
 		txd->ccfg |= ch->signal << PL080_CONFIG_SRC_SEL_SHIFT;
 
-	plchan->phychan_hold++;
-
 	return 0;
 }
 
@@ -938,8 +940,6 @@ static dma_cookie_t pl08x_tx_submit(struct dma_async_tx_descriptor *tx)
 		/* Do this memcpy whenever there is a channel ready */
 		plchan->state = PL08X_CHAN_WAITING;
 		plchan->waiting = txd;
-	} else {
-		plchan->phychan_hold--;
 	}
 
 	spin_unlock_irqrestore(&plchan->lock, flags);
@@ -1428,6 +1428,7 @@ static int pl08x_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 			 * Mark physical channel as free and free any slave
 			 * signal
 			 */
+			plchan->phychan_hold = 0;
 			release_phy_channel(plchan);
 		}
 		/* Dequeue jobs and free LLIs */
@@ -1529,6 +1530,7 @@ static void pl08x_tasklet(unsigned long data)
 	if (txd) {
 		/* Update last completed */
 		dma_cookie_complete(&txd->tx);
+		plchan->phychan_hold--;
 	}
 
 	/* If a new descriptor is queued, set it up plchan->at is NULL here */
-- 
1.7.4.4