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Subject[PATCH 3/4] spi: spi-qcom-qspi: Call dma_wmb() after setting up descriptors
Date
After setting up dma descriptors and before initiaiting dma transfer, call
dma_wmb() to ensure all writes go through.
This doesn't fix any reported problem but is added for safety.

Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>
---
drivers/spi/spi-qcom-qspi.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
index b938908..d75234d 100644
--- a/drivers/spi/spi-qcom-qspi.c
+++ b/drivers/spi/spi-qcom-qspi.c
@@ -443,8 +443,10 @@ static int qcom_qspi_transfer_one(struct spi_master *master,

ret = qcom_qspi_setup_dma_desc(ctrl, xfer);
if (ret != -EAGAIN) {
- if (!ret)
+ if (!ret) {
+ dma_wmb();
qcom_qspi_dma_xfer(ctrl);
+ }
goto exit;
}
dev_warn_once(ctrl->dev, "DMA failure, falling back to PIO\n");
--
Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by the Linux Foundation.
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