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Subject[PATCH] dma/imx-sdma: add wmb before enable/run a channel
Date
dma_alloc_coherent memory may be bufferable. We need to add
nececcary memory barrier.

Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
---
drivers/dma/imx-sdma.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 2ebb2bc..8cd9492 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -403,6 +403,7 @@ static int sdma_run_channel(struct sdma_channel *sdmac)

init_completion(&sdmac->done);

+ wmb();
__raw_writel(1 << channel, sdma->regs + SDMA_H_START);

ret = wait_for_completion_timeout(&sdmac->done, HZ);
@@ -809,6 +810,7 @@ out:

static void sdma_enable_channel(struct sdma_engine *sdma, int channel)
{
+ wmb();
__raw_writel(1 << channel, sdma->regs + SDMA_H_START);
}

--
1.7.4.1


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