From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> [ Upstream commit 9d32497361ff89d2fc8306407de6f04b2bfb2836 ] 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. Acked-By: Chris Lew <clew@xxxxxxxxxxxxxx> Reported-by: Arun Kumar Neelakantam <aneela@xxxxxxxxxxxxxx> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> --- 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 b1c15c64cdec3..c2a4467b5fcdf 100644 --- a/drivers/rpmsg/qcom_glink_smem.c +++ b/drivers/rpmsg/qcom_glink_smem.c @@ -185,6 +185,9 @@ 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); } -- 2.25.1