diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 2d6f008adb07..e10ff219aa5e 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -496,6 +496,7 @@ static int cqspi_read_setup(struct spi_nor *nor)
 	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
 	reg |= (nor->addr_width - 1);
 	writel(reg, reg_base + CQSPI_REG_SIZE);
+	readl(reg_base + CQSPI_REG_SIZE); /* Flush posted write. */
 	return 0;
 }
 
@@ -609,6 +610,7 @@ static int cqspi_write_setup(struct spi_nor *nor)
 	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
 	reg |= (nor->addr_width - 1);
 	writel(reg, reg_base + CQSPI_REG_SIZE);
+	readl(reg_base + CQSPI_REG_SIZE); /* Flush posted write. */
 	return 0;
 }