| Message ID | 20201212135733.38050-1-paul@crapouillou.net (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | clk: ingenic: Fix divider calculation with div tables | expand |
Quoting Paul Cercueil (2020-12-12 05:57:33) > The previous code assumed that a higher hardware value always resulted > in a bigger divider, which is correct for the regular clocks, but is > an invalid assumption when a divider table is provided for the clock. > > Perfect example of this is the PLL0_HALF clock, which applies a /2 > divider with the hardware value 0, and a /1 divider otherwise. > > Fixes: a9fa2893fcc6 ("clk: ingenic: Add support for divider tables") > Cc: <stable@vger.kernel.org> # 5.2 > Signed-off-by: Paul Cercueil <paul@crapouillou.net> > --- Applied to clk-next
diff --git a/drivers/clk/ingenic/cgu.c b/drivers/clk/ingenic/cgu.c index dac6edc670cc..c8e9cb6c8e39 100644 --- a/drivers/clk/ingenic/cgu.c +++ b/drivers/clk/ingenic/cgu.c @@ -392,15 +392,21 @@ static unsigned int ingenic_clk_calc_hw_div(const struct ingenic_cgu_clk_info *clk_info, unsigned int div) { - unsigned int i; + unsigned int i, best_i = 0, best = (unsigned int)-1; for (i = 0; i < (1 << clk_info->div.bits) && clk_info->div.div_table[i]; i++) { - if (clk_info->div.div_table[i] >= div) - return i; + if (clk_info->div.div_table[i] >= div && + clk_info->div.div_table[i] < best) { + best = clk_info->div.div_table[i]; + best_i = i; + + if (div == best) + break; + } } - return i - 1; + return best_i; } static unsigned
The previous code assumed that a higher hardware value always resulted in a bigger divider, which is correct for the regular clocks, but is an invalid assumption when a divider table is provided for the clock. Perfect example of this is the PLL0_HALF clock, which applies a /2 divider with the hardware value 0, and a /1 divider otherwise. Fixes: a9fa2893fcc6 ("clk: ingenic: Add support for divider tables") Cc: <stable@vger.kernel.org> # 5.2 Signed-off-by: Paul Cercueil <paul@crapouillou.net> --- drivers/clk/ingenic/cgu.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)