linux-kernel - [PATCH 08/12] DMAENGINE: be more explicit when freeing PL08X signals

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Date:	Tue, 31 Aug 2010 14:12:10 +0200
From:	Linus Walleij <linus.walleij@...ricsson.com>
To:	Dan Williams <dan.j.williams@...el.com>,
	<linux-arm-kernel@...ts.infradead.org>, <yuanyabin1978@...a.com>
Cc:	<linux-kernel@...r.kernel.org>,
	Linus Walleij <linus.walleij@...ricsson.com>
Subject: [PATCH 08/12] DMAENGINE: be more explicit when freeing PL08X signals

The signals connected to the PL08X physical channels shall not
be tangled up with the physical channels themselves. This gets
some reference counting right.

Signed-off-by: Linus Walleij <linus.walleij@...ricsson.com>
---
 drivers/dma/amba-pl08x.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index a99ad19..a7ce08e 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -449,7 +449,6 @@ static inline void pl08x_put_phy_channel(struct pl08x_driver_data *pl08x,
 	/* Mark it as free */
 	spin_lock_irqsave(&ch->lock, flags);
 	ch->serving = NULL;
-	ch->signal = -1;
 	spin_unlock_irqrestore(&ch->lock, flags);
 }
 
@@ -1100,8 +1099,10 @@ static void pl08x_tasklet(unsigned long data)
 		 * No more jobs, so free up the physical channel
 		 * Free any allocated signal on slave transfers too
 		 */
-		if ((phychan->signal >= 0) && pl08x->pd->put_signal)
+		if ((phychan->signal >= 0) && pl08x->pd->put_signal) {
 			pl08x->pd->put_signal(plchan);
+			phychan->signal = -1;
+		}
 		pl08x_put_phy_channel(pl08x, phychan);
 		plchan->phychan = NULL;
 	}
@@ -1193,6 +1194,7 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
 	 */
 	if ((txd->direction == DMA_FROM_DEVICE ||
 	     txd->direction == DMA_TO_DEVICE) &&
+	    ch->signal < 0 &&
 	    pl08x->pd->get_signal) {
 		ret = pl08x->pd->get_signal(plchan);
 		if (ret < 0) {
@@ -1653,8 +1655,10 @@ static int pl08x_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 			 * signal
 			 */
 			if ((plchan->phychan->signal >= 0) &&
-			    pl08x->pd->put_signal)
+			    pl08x->pd->put_signal) {
 				pl08x->pd->put_signal(plchan);
+				plchan->phychan->signal = -1;
+			}
 			pl08x_put_phy_channel(pl08x, plchan->phychan);
 			plchan->phychan = NULL;
 		}
-- 
1.6.3.3

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