This is a note to let you know that I've just added the patch titled
dmaengine: pl330: issue_pending waits until WFP state
to the 4.19-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-pl330-issue_pending-waits-until-wfp-state.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit beef5300cedf64ce8efc40386e2e76de5d8c7568
Author: Bumyong Lee <bumyong.lee@xxxxxxxxxxx>
Date: Tue Dec 19 14:50:26 2023 +0900
dmaengine: pl330: issue_pending waits until WFP state
[ Upstream commit 22a9d9585812440211b0b34a6bc02ade62314be4 ]
According to DMA-330 errata notice[1] 71930, DMAKILL
cannot clear internal signal, named pipeline_req_active.
it makes that pl330 would wait forever in WFP state
although dma already send dma request if pl330 gets
dma request before entering WFP state.
The errata suggests that polling until entering WFP state
as workaround and then peripherals allows to issue dma request.
[1]: https://developer.arm.com/documentation/genc008428/latest
Signed-off-by: Bumyong Lee <bumyong.lee@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231219055026.118695-1-bumyong.lee@xxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Stable-dep-of: afc89870ea67 ("dmaengine: Revert "dmaengine: pl330: issue_pending waits until WFP state"")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 1bba1fa3a8096..54bb6e46c1803 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1045,6 +1045,9 @@ static bool _trigger(struct pl330_thread *thrd)
thrd->req_running = idx;
+ if (desc->rqtype == DMA_MEM_TO_DEV || desc->rqtype == DMA_DEV_TO_MEM)
+ UNTIL(thrd, PL330_STATE_WFP);
+
return true;
}
