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Commit a81a1935 authored by Xinwei Kong's avatar Xinwei Kong Committed by Greg Kroah-Hartman
Browse files

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



[ 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: 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.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent cfad68d1

drivers/spi/spi-dw.c

+3 −0
Original line number Diff line number Diff line
@@ -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 */