diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 6783e12c40c2..a556795caeef 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -36,7 +36,6 @@
 #define SPI_CFG0_SCK_LOW_OFFSET           8
 #define SPI_CFG0_CS_HOLD_OFFSET           16
 #define SPI_CFG0_CS_SETUP_OFFSET          24
-#define SPI_ADJUST_CFG0_SCK_LOW_OFFSET    16
 #define SPI_ADJUST_CFG0_CS_HOLD_OFFSET    0
 #define SPI_ADJUST_CFG0_CS_SETUP_OFFSET   16
 
@@ -48,6 +47,8 @@
 #define SPI_CFG1_CS_IDLE_MASK             0xff
 #define SPI_CFG1_PACKET_LOOP_MASK         0xff00
 #define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
+#define SPI_CFG2_SCK_HIGH_OFFSET          0
+#define SPI_CFG2_SCK_LOW_OFFSET           16
 
 #define SPI_CMD_ACT                  BIT(0)
 #define SPI_CMD_RESUME               BIT(1)
@@ -283,7 +284,7 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
 static void mtk_spi_prepare_transfer(struct spi_master *master,
 				     struct spi_transfer *xfer)
 {
-	u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0;
+	u32 spi_clk_hz, div, sck_time, cs_time, reg_val;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 
 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
@@ -296,18 +297,18 @@ static void mtk_spi_prepare_transfer(struct spi_master *master,
 	cs_time = sck_time * 2;
 
 	if (mdata->dev_comp->enhance_timing) {
+		reg_val = (((sck_time - 1) & 0xffff)
+			   << SPI_CFG2_SCK_HIGH_OFFSET);
 		reg_val |= (((sck_time - 1) & 0xffff)
-			   << SPI_CFG0_SCK_HIGH_OFFSET);
-		reg_val |= (((sck_time - 1) & 0xffff)
-			   << SPI_ADJUST_CFG0_SCK_LOW_OFFSET);
+			   << SPI_CFG2_SCK_LOW_OFFSET);
 		writel(reg_val, mdata->base + SPI_CFG2_REG);
-		reg_val |= (((cs_time - 1) & 0xffff)
+		reg_val = (((cs_time - 1) & 0xffff)
 			   << SPI_ADJUST_CFG0_CS_HOLD_OFFSET);
 		reg_val |= (((cs_time - 1) & 0xffff)
 			   << SPI_ADJUST_CFG0_CS_SETUP_OFFSET);
 		writel(reg_val, mdata->base + SPI_CFG0_REG);
 	} else {
-		reg_val |= (((sck_time - 1) & 0xff)
+		reg_val = (((sck_time - 1) & 0xff)
 			   << SPI_CFG0_SCK_HIGH_OFFSET);
 		reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
 		reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index ecea15534c42..fa11cc0e809b 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -198,7 +198,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 				  struct spi_transfer *tfr)
 {
 	struct sun6i_spi *sspi = spi_master_get_devdata(master);
-	unsigned int mclk_rate, div, timeout;
+	unsigned int mclk_rate, div, div_cdr1, div_cdr2, timeout;
 	unsigned int start, end, tx_time;
 	unsigned int trig_level;
 	unsigned int tx_len = 0;
@@ -287,14 +287,12 @@ static int sun6i_spi_transfer_one(struct spi_master *master,
 	 * First try CDR2, and if we can't reach the expected
 	 * frequency, fall back to CDR1.
 	 */
-	div = mclk_rate / (2 * tfr->speed_hz);
-	if (div <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
-		if (div > 0)
-			div--;
-
-		reg = SUN6I_CLK_CTL_CDR2(div) | SUN6I_CLK_CTL_DRS;
+	div_cdr1 = DIV_ROUND_UP(mclk_rate, tfr->speed_hz);
+	div_cdr2 = DIV_ROUND_UP(div_cdr1, 2);
+	if (div_cdr2 <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
+		reg = SUN6I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN6I_CLK_CTL_DRS;
 	} else {
-		div = ilog2(mclk_rate) - ilog2(tfr->speed_hz);
+		div = min(SUN6I_CLK_CTL_CDR1_MASK, order_base_2(div_cdr1));
 		reg = SUN6I_CLK_CTL_CDR1(div);
 	}