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Subject[PATCH 4.9 054/121] dmaengine: tegra-apb: Prevent race conditions on channels freeing
Date
From: Dmitry Osipenko <digetx@gmail.com>

[ Upstream commit 8e84172e372bdca20c305d92d51d33640d2da431 ]

It's incorrect to check the channel's "busy" state without taking a lock.
That shouldn't cause any real troubles, nevertheless it's always better
not to have any race conditions in the code.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20200209163356.6439-5-digetx@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/dma/tegra20-apb-dma.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 4eaf92b2b8868..909739426f78c 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -1208,8 +1208,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)

dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);

- if (tdc->busy)
- tegra_dma_terminate_all(dc);
+ tegra_dma_terminate_all(dc);

spin_lock_irqsave(&tdc->lock, flags);
list_splice_init(&tdc->pending_sg_req, &sg_req_list);
--
2.25.1


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