From 3dc0530e2940a40eecccde9e9e1ab7c0bdc4e4b8 Mon Sep 17 00:00:00 2001 From: Xinwei Kong Date: Tue, 22 Sep 2020 10:21:11 +0800 Subject: [PATCH] spi: dw: use "smp_mb()" to avoid sending spi data error stable inclusion from linux-4.19.127 commit a81a1935d135de42c4fa34b640d787e0774be35b -------------------------------- [ Upstream commit bfda044533b213985bc62bd7ca96f2b984d21b80 ] Because of out-of-order execution about some CPU architecture, In this debug stage we find Completing spi interrupt enable -> prodrucing TXEI interrupt -> running "interrupt_transfer" function will prior to set "dw->rx and dws->rx_end" data, so this patch add memory barrier to enable dw->rx and dw->rx_end to be visible and solve to send SPI data error. eg: it will fix to this following low possibility error in testing environment which using SPI control to connect TPM Modules kernel: tpm tpm0: Operation Timed out kernel: tpm tpm0: tpm_relinquish_locality: : error -1 Signed-off-by: fengsheng Signed-off-by: Xinwei Kong Link: https://lore.kernel.org/r/1578019930-55858-1-git-send-email-kong.kongxinwei@hisilicon.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin Signed-off-by: Yang Yingliang --- drivers/spi/spi-dw.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index c623998ed93f..a0168b36ace4 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -304,6 +304,9 @@ static int dw_spi_transfer_one(struct spi_controller *master, dws->len = transfer->len; spin_unlock_irqrestore(&dws->buf_lock, flags); + /* Ensure dw->rx and dw->rx_end are visible */ + smp_mb(); + spi_enable_chip(dws, 0); /* Handle per transfer options for bpw and speed */ -- GitLab