dmaengine: PL08x: re-jig the starting of txds
Rather than code the de-queue of the txd several times, move that into
the start_txd function. Rename this to better illustrate what it's
now doing, and call this function when starting a delayed memcpy().
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 88661fa..c278d23a 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -354,20 +354,25 @@
* been set when the LLIs were constructed. Poke them into the hardware
* and start the transfer.
*/
-static void pl08x_start_txd(struct pl08x_dma_chan *plchan,
- struct pl08x_txd *txd)
+static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
{
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_phy_chan *phychan = plchan->phychan;
- struct pl08x_lli *lli = &txd->llis_va[0];
+ struct pl08x_lli *lli;
+ struct pl08x_txd *txd;
u32 val;
+ txd = list_first_entry(&plchan->pend_list, struct pl08x_txd, node);
+ list_del(&txd->node);
+
plchan->at = txd;
/* Wait for channel inactive */
while (pl08x_phy_channel_busy(phychan))
cpu_relax();
+ lli = &txd->llis_va[0];
+
dev_vdbg(&pl08x->adev->dev,
"WRITE channel %d: csrc=0x%08x, cdst=0x%08x, "
"clli=0x%08x, cctl=0x%08x, ccfg=0x%08x\n",
@@ -1272,15 +1277,8 @@
/* Take the first element in the queue and execute it */
if (!list_empty(&plchan->pend_list)) {
- struct pl08x_txd *next;
-
- next = list_first_entry(&plchan->pend_list,
- struct pl08x_txd,
- node);
- list_del(&next->node);
plchan->state = PL08X_CHAN_RUNNING;
-
- pl08x_start_txd(plchan, next);
+ pl08x_start_next_txd(plchan);
}
spin_unlock_irqrestore(&plchan->lock, flags);
@@ -1661,14 +1659,7 @@
/* If a new descriptor is queued, set it up plchan->at is NULL here */
if (!list_empty(&plchan->pend_list)) {
- struct pl08x_txd *next;
-
- next = list_first_entry(&plchan->pend_list,
- struct pl08x_txd,
- node);
- list_del(&next->node);
-
- pl08x_start_txd(plchan, next);
+ pl08x_start_next_txd(plchan);
} else if (plchan->phychan_hold) {
/*
* This channel is still in use - we have a new txd being
@@ -1700,7 +1691,13 @@
BUG_ON(ret);
waiting->phychan_hold--;
waiting->state = PL08X_CHAN_RUNNING;
- pl08x_issue_pending(&waiting->chan);
+ /*
+ * Eww. We know this isn't going to deadlock
+ * but lockdep probably doens't.
+ */
+ spin_lock(&waiting->lock);
+ pl08x_start_next_txd(waiting);
+ spin_unlock(&waiting->lock);
break;
}
}