Re: [PATCH v4 2/3] clk: nuvoton: ma35d1: fix PLL_CTL1_FRAC bit field width and fractional calc
Alexandre Mergnat <[email protected]>
| Newsgroups | org.kernel.vger.linux-clk,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <178465175574.2337945.7396666795379567940.b4-review@b4> |
On Tue, 21 Jul 2026 10:13:55 +0800, Joey Lu <[email protected]> wrote: > PLL_CTL1_FRAC was defined as GENMASK(31, 24), covering only 8 bits. > The hardware fractional field occupies bits [31:8] (24 bits), so the > mask must be GENMASK(31, 8). > > The previous fractional-mode calculation used FIELD_MAX(PLL_CTL1_FRAC) > as the denominator to obtain 2 decimal places. With the corrected 24-bit > mask the old divisor is wrong; replace the arithmetic with a proper > 24-bit fixed-point rounding to 3 decimal places using the kernel's > DIV_ROUND_CLOSEST_ULL helper: > > [...] Reviewed-by: Alexandre Mergnat <[email protected]> -- Alexandre Mergnat <[email protected]>