This is a note to let you know that I've just added the patch titled
dmaengine: dw-edma: Fix to change for continuous transfer
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dmaengine-dw-edma-fix-to-change-for-continuous-trans.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f424ab31e479a8f17ad7a2ec985d254d5d943d53
Author: Shunsuke Mie <mie@xxxxxxxxxx>
Date: Tue Apr 11 19:17:57 2023 +0900
dmaengine: dw-edma: Fix to change for continuous transfer
[ Upstream commit a251994a441ee0a69ba7062c8cd2d08ead3db379 ]
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.
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 <mie@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230411101758.438472-1-mie@xxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 97f5e4e93cfc6..2a434c255b4a2 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -171,7 +171,7 @@ 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;
@@ -179,16 +179,16 @@ 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;
@@ -196,6 +196,8 @@ 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,
@@ -555,14 +557,14 @@ 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 transferring if there are remaining chunks or issued requests.
+ */
+ chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
break;
case EDMA_REQ_STOP:
