| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 437/453] clk: ingenic: Fix divider calculation with div tables | Date | Mon, 28 Dec 2020 13:51:13 +0100 |
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From: Paul Cercueil <paul@crapouillou.net>
commit 11a163f2c7d6a9f27ce144cd7e367a81c851621a upstream.
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> Link: https://lore.kernel.org/r/20201212135733.38050-1-paul@crapouillou.net Signed-off-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/clk/ingenic/cgu.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
--- a/drivers/clk/ingenic/cgu.c +++ b/drivers/clk/ingenic/cgu.c @@ -393,15 +393,21 @@ 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
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