Currently, the for-loop used to try all the different dividers to find the one that best fit tries all the values from 1 to max_div, incrementing by one. In case of power-of-two, or table based divider, the loop isn't optimal.
Instead of incrementing by one, this patch provides directly the next divider. Signed-off-by: Maxime Coquelin <[email protected]> --- drivers/clk/clk-divider.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 1eaa5d8..4aabf4f 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -240,6 +240,18 @@ static bool _is_best_div(struct clk_divider *divider, return now <= rate && now > best; } +static int _next_div(struct clk_divider *divider, int div) +{ + div++; + + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + return __roundup_pow_of_two(div); + if (divider->table) + return _round_up_table(divider->table, div); + + return div; +} + static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, unsigned long *best_parent_rate) { @@ -267,7 +279,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, */ maxdiv = min(ULONG_MAX / rate, maxdiv); - for (i = 1; i <= maxdiv; i++) { + for (i = 1; i <= maxdiv; i = _next_div(divider, i)) { if (!_is_valid_div(divider, i)) continue; if (rate * i == parent_rate_saved) { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
