[PATCH 5.4 01/84] dmaengine: pl330: issue_pending waits until WFP state

Greg Kroah-Hartman
2024-05-14T11:42:15Z

From: Bumyong Lee <bumyong.lee@samsung.com>

[ 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@samsung.com>
Link: https://lore.kernel.org/r/20231219055026.118695-1-bumyong.lee@samsung.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Stable-dep-of: afc89870ea67 ("dmaengine: Revert "dmaengine: pl330: issue_pending waits until WFP state"")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/pl330.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 1d7d4b8d810a5..d12939c25a618 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1051,6 +1051,9 @@ 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;
}

--
2.43.0