[ 3.8.y.z extended stable ] Patch "dma: pl330: Fix cyclic transfers" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    dma: pl330: Fix cyclic transfers

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 199d8d653f995e08b733e475d1573b3da8c0c442 Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars at metafoo.de>
Date: Tue, 23 Jul 2013 10:24:50 +0200
Subject: dma: pl330: Fix cyclic transfers

commit fc51446021f42aca8906e701fc2292965aafcb15 upstream.

Allocate a descriptor for each period of a cyclic transfer, not just the first.
Also since the callback needs to be called for each finished period make sure to
initialize the callback and callback_param fields of each descriptor in a cyclic
transfer.

Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/dma/pl330.c | 93 ++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 67 insertions(+), 26 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 4bed3f1..9cfe424 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2501,6 +2501,10 @@ static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx)
 	/* Assign cookies to all nodes */
 	while (!list_empty(&last->node)) {
 		desc = list_entry(last->node.next, struct dma_pl330_desc, node);
+		if (pch->cyclic) {
+			desc->txd.callback = last->txd.callback;
+			desc->txd.callback_param = last->txd.callback_param;
+		}

 		dma_cookie_assign(&desc->txd);

@@ -2684,45 +2688,82 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
 		size_t period_len, enum dma_transfer_direction direction,
 		unsigned long flags, void *context)
 {
-	struct dma_pl330_desc *desc;
+	struct dma_pl330_desc *desc = NULL, *first = NULL;
 	struct dma_pl330_chan *pch = to_pchan(chan);
+	struct dma_pl330_dmac *pdmac = pch->dmac;
+	unsigned int i;
 	dma_addr_t dst;
 	dma_addr_t src;

-	desc = pl330_get_desc(pch);
-	if (!desc) {
-		dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n",
-			__func__, __LINE__);
+	if (len % period_len != 0)
 		return NULL;
-	}

-	switch (direction) {
-	case DMA_MEM_TO_DEV:
-		desc->rqcfg.src_inc = 1;
-		desc->rqcfg.dst_inc = 0;
-		desc->req.rqtype = MEMTODEV;
-		src = dma_addr;
-		dst = pch->fifo_addr;
-		break;
-	case DMA_DEV_TO_MEM:
-		desc->rqcfg.src_inc = 0;
-		desc->rqcfg.dst_inc = 1;
-		desc->req.rqtype = DEVTOMEM;
-		src = pch->fifo_addr;
-		dst = dma_addr;
-		break;
-	default:
+	if (!is_slave_direction(direction)) {
 		dev_err(pch->dmac->pif.dev, "%s:%d Invalid dma direction\n",
 		__func__, __LINE__);
 		return NULL;
 	}

-	desc->rqcfg.brst_size = pch->burst_sz;
-	desc->rqcfg.brst_len = 1;
+	for (i = 0; i < len / period_len; i++) {
+		desc = pl330_get_desc(pch);
+		if (!desc) {
+			dev_err(pch->dmac->pif.dev, "%s:%d Unable to fetch desc\n",
+				__func__, __LINE__);

-	pch->cyclic = true;
+			if (!first)
+				return NULL;
+
+			spin_lock_irqsave(&pdmac->pool_lock, flags);
+
+			while (!list_empty(&first->node)) {
+				desc = list_entry(first->node.next,
+						struct dma_pl330_desc, node);
+				list_move_tail(&desc->node, &pdmac->desc_pool);
+			}
+
+			list_move_tail(&first->node, &pdmac->desc_pool);

-	fill_px(&desc->px, dst, src, period_len);
+			spin_unlock_irqrestore(&pdmac->pool_lock, flags);
+
+			return NULL;
+		}
+
+		switch (direction) {
+		case DMA_MEM_TO_DEV:
+			desc->rqcfg.src_inc = 1;
+			desc->rqcfg.dst_inc = 0;
+			desc->req.rqtype = MEMTODEV;
+			src = dma_addr;
+			dst = pch->fifo_addr;
+			break;
+		case DMA_DEV_TO_MEM:
+			desc->rqcfg.src_inc = 0;
+			desc->rqcfg.dst_inc = 1;
+			desc->req.rqtype = DEVTOMEM;
+			src = pch->fifo_addr;
+			dst = dma_addr;
+			break;
+		default:
+			break;
+		}
+
+		desc->rqcfg.brst_size = pch->burst_sz;
+		desc->rqcfg.brst_len = 1;
+		fill_px(&desc->px, dst, src, period_len);
+
+		if (!first)
+			first = desc;
+		else
+			list_add_tail(&desc->node, &first->node);
+
+		dma_addr += period_len;
+	}
+
+	if (!desc)
+		return NULL;
+
+	pch->cyclic = true;
+	desc->txd.flags = flags;

 	return &desc->txd;
 }
--
1.8.1.2