[PATCH] spi: dw: Fix missing smp_mb() in dw_spi_exec_mem_op

[Jisheng Zhang <jszhang@kernel.org>]

Similar as commit bfda044533b2 ("spi: dw: use "smp_mb()" to avoid
sending spi data error"), we also need the smp_mb() in
dw_spi_exec_mem_op() after setting up the members in "dws" to ensure
the data change is visible for all CPUs.

Fixes: 6423207e57ea ("spi: dw: Add memory operations support")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 drivers/spi/spi-dw-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
index 2d671e31413e..90af2cc9e17d 100644
--- a/drivers/spi/spi-dw-core.c
+++ b/drivers/spi/spi-dw-core.c
@@ -842,6 +842,9 @@ static int dw_spi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
 		cfg.tmode = DW_SPI_CTRLR0_TMOD_TO;
 	}
 
+	/* Ensure the data change in dw_spi_init_mem_buf() is visible for all CPUs */
+	smp_mb();
+
 	dw_spi_enable_chip(dws, 0);
 
 	dw_spi_update_config(dws, mem->spi, &cfg, NULL);
-- 
2.53.0