diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index aa6789f53774..95548a40d8ca 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -569,8 +569,8 @@ static void rockchip_spi_config(struct rockchip_spi *rs,
 	 * interrupt exactly when the fifo is full doesn't seem to work,
 	 * so we need the strict inequality here
 	 */
-	if (xfer->len < rs->fifo_len)
-		writel_relaxed(xfer->len - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
+	if ((xfer->len / rs->n_bytes) < rs->fifo_len)
+		writel_relaxed(xfer->len / rs->n_bytes - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 	else
 		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);