Commit bfda0445 authored by Xinwei Kong's avatar Xinwei Kong Committed by Mark Brown

spi: dw: use "smp_mb()" to avoid sending spi data error

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: default avatarfengsheng <fengsheng5@huawei.com>
Signed-off-by: default avatarXinwei Kong <kong.kongxinwei@hisilicon.com>
Link: https://lore.kernel.org/r/1578019930-55858-1-git-send-email-kong.kongxinwei@hisilicon.comSigned-off-by: default avatarMark Brown <broonie@kernel.org>
parent 09b6636c
...@@ -297,6 +297,9 @@ static int dw_spi_transfer_one(struct spi_controller *master, ...@@ -297,6 +297,9 @@ static int dw_spi_transfer_one(struct spi_controller *master,
dws->len = transfer->len; dws->len = transfer->len;
spin_unlock_irqrestore(&dws->buf_lock, flags); spin_unlock_irqrestore(&dws->buf_lock, flags);
/* Ensure dw->rx and dw->rx_end are visible */
smp_mb();
spi_enable_chip(dws, 0); spi_enable_chip(dws, 0);
/* Handle per transfer options for bpw and speed */ /* Handle per transfer options for bpw and speed */
......
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