From bc5d922c93491878c44c9216e9d227c7eeb81d7f Mon Sep 17 00:00:00 2001 From: Paul Cercueil Date: Sun, 27 Jan 2019 23:09:20 -0300 Subject: clk: ingenic: Fix round_rate misbehaving with non-integer dividers Take a parent rate of 180 MHz, and a requested rate of 4.285715 MHz. This results in a theorical divider of 41.999993 which is then rounded up to 42. The .round_rate function would then return (180 MHz / 42) as the clock, rounded down, so 4.285714 MHz. Calling clk_set_rate on 4.285714 MHz would round the rate again, and give a theorical divider of 42,0000028, now rounded up to 43, and the rate returned would be (180 MHz / 43) which is 4.186046 MHz, aka. not what we requested. Fix this by rounding up the divisions. Signed-off-by: Paul Cercueil Tested-by: Maarten ter Huurne Cc: Signed-off-by: Stephen Boyd --- drivers/clk/ingenic/cgu.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'drivers/clk') diff --git a/drivers/clk/ingenic/cgu.c b/drivers/clk/ingenic/cgu.c index 5ef7d9ba2195..b40160eb3372 100644 --- a/drivers/clk/ingenic/cgu.c +++ b/drivers/clk/ingenic/cgu.c @@ -426,16 +426,16 @@ ingenic_clk_round_rate(struct clk_hw *hw, unsigned long req_rate, struct ingenic_clk *ingenic_clk = to_ingenic_clk(hw); struct ingenic_cgu *cgu = ingenic_clk->cgu; const struct ingenic_cgu_clk_info *clk_info; - long rate = *parent_rate; + unsigned int div = 1; clk_info = &cgu->clock_info[ingenic_clk->idx]; if (clk_info->type & CGU_CLK_DIV) - rate /= ingenic_clk_calc_div(clk_info, *parent_rate, req_rate); + div = ingenic_clk_calc_div(clk_info, *parent_rate, req_rate); else if (clk_info->type & CGU_CLK_FIXDIV) - rate /= clk_info->fixdiv.div; + div = clk_info->fixdiv.div; - return rate; + return DIV_ROUND_UP(*parent_rate, div); } static int @@ -455,7 +455,7 @@ ingenic_clk_set_rate(struct clk_hw *hw, unsigned long req_rate, if (clk_info->type & CGU_CLK_DIV) { div = ingenic_clk_calc_div(clk_info, parent_rate, req_rate); - rate = parent_rate / div; + rate = DIV_ROUND_UP(parent_rate, div); if (rate != req_rate) return -EINVAL; -- cgit v1.2.3-59-g8ed1b