[PATCH v3 1/3] clk: nuvoton: ma35d1: fix ignored div_u64 return values in PLL freq calculation

Joey Lu a0987203069 at gmail.com
Wed May 20 18:42:18 PDT 2026


div_u64() does not modify its argument in place; the return value must
be assigned.  Both ma35d1_calc_smic_pll_freq() and ma35d1_calc_pll_freq()
called div_u64() and discarded the result, leaving pll_freq holding the
undivided product and thus returning a frequency orders of magnitude too
high.

Fixes: 691521a367cf ("clk: nuvoton: Add clock driver for ma35d1 clock controller")

Reviewed-by: Brian Masney <bmasney at redhat.com>
Signed-off-by: Joey Lu <a0987203069 at gmail.com>
---
 drivers/clk/nuvoton/clk-ma35d1-pll.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/nuvoton/clk-ma35d1-pll.c b/drivers/clk/nuvoton/clk-ma35d1-pll.c
index 4620acfe47e8..bfedd45bd04b 100644
--- a/drivers/clk/nuvoton/clk-ma35d1-pll.c
+++ b/drivers/clk/nuvoton/clk-ma35d1-pll.c
@@ -92,7 +92,7 @@ static unsigned long ma35d1_calc_smic_pll_freq(u32 pll0_ctl0,
 	p = FIELD_GET(SPLL0_CTL0_OUTDIV, pll0_ctl0);
 	outdiv = 1 << p;
 	pll_freq = (u64)parent_rate * n;
-	div_u64(pll_freq, m * outdiv);
+	pll_freq = div_u64(pll_freq, m * outdiv);
 	return pll_freq;
 }
 
@@ -110,7 +110,7 @@ static unsigned long ma35d1_calc_pll_freq(u8 mode, u32 *reg_ctl, unsigned long p
 
 	if (mode == PLL_MODE_INT) {
 		pll_freq = (u64)parent_rate * n;
-		div_u64(pll_freq, m * p);
+		pll_freq = div_u64(pll_freq, m * p);
 	} else {
 		x = FIELD_GET(PLL_CTL1_FRAC, reg_ctl[1]);
 		/* 2 decimal places floating to integer (ex. 1.23 to 123) */
-- 
2.43.0




More information about the linux-arm-kernel mailing list