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Subject[PATCH resend] dma: pl330: Fix cyclic transfers
Date
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.

Cc: stable@vger.kernel.org
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
drivers/dma/pl330.c | 87 ++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 66 insertions(+), 21 deletions(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 7c02e83..29d4476 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2505,6 +2505,10 @@ 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);

@@ -2688,32 +2692,19 @@ 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:
dev_err(pch->dmac->pif.dev, "%s:%d Invalid dma direction\n",
@@ -2721,12 +2712,66 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
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;

- fill_px(&desc->px, dst, src, period_len);
+ 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);
+
+ 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;
}
--
1.8.0


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