2022-12-23 02:38:11

by Shunsuke Mie

Subject: [PATCH 1/2] dmaengine: dw-edma: Fix to change for continuous transfer

The dw-edma driver stops after processing a DMA request even if a request
remains in the issued queue, which is not the expected behavior. The DMA
engine API requires continuous processing.

Fix it to add a trigger to start after one processing finished if there are
requests remain.

Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
Signed-off-by: Shunsuke Mie <[email protected]>
---
drivers/dma/dw-edma/dw-edma-core.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index c54b24ff5206..669b97313911 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -170,7 +170,7 @@ static void vchan_free_desc(struct virt_dma_desc *vdesc)
dw_edma_free_desc(vd2dw_edma_desc(vdesc));
}

-static void dw_edma_start_transfer(struct dw_edma_chan *chan)
+static int dw_edma_start_transfer(struct dw_edma_chan *chan)
{
struct dw_edma_chunk *child;
struct dw_edma_desc *desc;
@@ -178,16 +178,16 @@ static void dw_edma_start_transfer(struct dw_edma_chan *chan)

vd = vchan_next_desc(&chan->vc);
if (!vd)
- return;
+ return 0;

desc = vd2dw_edma_desc(vd);
if (!desc)
- return;
+ return 0;

child = list_first_entry_or_null(&desc->chunk->list,
struct dw_edma_chunk, list);
if (!child)
- return;
+ return 0;

dw_edma_v0_core_start(child, !desc->xfer_sz);
desc->xfer_sz += child->ll_region.sz;
@@ -195,6 +195,8 @@ static void dw_edma_start_transfer(struct dw_edma_chan *chan)
list_del(&child->list);
kfree(child);
desc->chunks_alloc--;
+
+ return 1;
}

static int dw_edma_device_config(struct dma_chan *dchan,
@@ -568,14 +570,17 @@ static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
switch (chan->request) {
case EDMA_REQ_NONE:
desc = vd2dw_edma_desc(vd);
- if (desc->chunks_alloc) {
- chan->status = EDMA_ST_BUSY;
- dw_edma_start_transfer(chan);
- } else {
+ if (!desc->chunks_alloc) {
list_del(&vd->node);
vchan_cookie_complete(vd);
- chan->status = EDMA_ST_IDLE;
}
+
+ /* Continue to transfer in case of there are rest chunks, or issued
+ * requests remain.
+ */
+ chan->status = EDMA_ST_BUSY;
+ if (!dw_edma_start_transfer(chan))
+ chan->status = EDMA_ST_IDLE;
break;

case EDMA_REQ_STOP:
--
2.25.1

2022-12-23 02:38:30

by Shunsuke Mie

Subject: [PATCH 2/2] dmaengine: dw-edma: Fix to enable to issue dma request on DMA processing

The issue_pending request is ignored while driver is processing a DMA
request. Fix to issue the pending requests on any dma channel status.

Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
Signed-off-by: Shunsuke Mie <[email protected]>
---
drivers/dma/dw-edma/dw-edma-core.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 669b97313911..80323b7a8bce 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -279,9 +279,12 @@ static void dw_edma_device_issue_pending(struct dma_chan *dchan)
struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
unsigned long flags;

+ if (!chan->configured)
+ return;
+
spin_lock_irqsave(&chan->vc.lock, flags);
- if (chan->configured && chan->request == EDMA_REQ_NONE &&
- chan->status == EDMA_ST_IDLE && vchan_issue_pending(&chan->vc)) {
+ if (vchan_issue_pending(&chan->vc) && chan->request == EDMA_REQ_NONE &&
+ chan->status == EDMA_ST_IDLE) {
chan->status = EDMA_ST_BUSY;
dw_edma_start_transfer(chan);
}
--
2.25.1