diff --git a/target/linux/ar71xx/files/drivers/spi/spi-rb4xx-cpld.c b/target/linux/ar71xx/files/drivers/spi/spi-rb4xx-cpld.c
index f6ec350525..0534c7c374 100644
--- a/target/linux/ar71xx/files/drivers/spi/spi-rb4xx-cpld.c
+++ b/target/linux/ar71xx/files/drivers/spi/spi-rb4xx-cpld.c
@@ -279,7 +279,7 @@ static int rb4xx_cpld_probe(struct spi_device *spi)
 	cpld->spi = spi_dev_get(spi);
 	dev_set_drvdata(&spi->dev, cpld);
 
-	spi->mode = SPI_MODE_0;
+	spi->mode = SPI_MODE_0 | SPI_TX_DUAL;
 	spi->bits_per_word = 8;
 	err = spi_setup(spi);
 	if (err) {