2017-12-14 20:15:54

by Bjorn Andersson

Subject: [PATCH] rpmsg: glink: smem: Ensure ordering during tx

Ensure the ordering of the fifo write and the update of the write index,
so that the index is not updated before the data has landed in the fifo.

Reported-by: Arun Kumar Neelakantam <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
---
drivers/rpmsg/qcom_glink_smem.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/rpmsg/qcom_glink_smem.c b/drivers/rpmsg/qcom_glink_smem.c
index 057528e23d3a..892f2b92a4d8 100644
--- a/drivers/rpmsg/qcom_glink_smem.c
+++ b/drivers/rpmsg/qcom_glink_smem.c
@@ -183,6 +183,9 @@ static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
if (head >= pipe->native.length)
head -= pipe->native.length;

+ /* Ensure ordering of fifo and head update */
+ wmb();
+
*pipe->head = cpu_to_le32(head);
}

--
2.15.0

2017-12-18 22:09:27

by Chris Lew

Subject: Re: [PATCH] rpmsg: glink: smem: Ensure ordering during tx

On 12/14/2017 12:15 PM, Bjorn Andersson wrote:
> Ensure the ordering of the fifo write and the update of the write index,
> so that the index is not updated before the data has landed in the fifo.
>
> Reported-by: Arun Kumar Neelakantam <[email protected]>
> Signed-off-by: Bjorn Andersson <[email protected]>
> ---

Acked-By: Chris Lew <[email protected]>

--
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